tag:blogger.com,1999:blog-87429446877334831082024-03-06T09:41:43.087+01:00Magic Squares, Spheres and ToriMagic Squares offer partial glimpses of the convex or concave number systems that they represent. Analysed using modular arithmetic, Magic Tori open new perspectives.William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.comBlogger49125tag:blogger.com,1999:blog-8742944687733483108.post-10546037156580089142023-06-15T11:45:00.007+02:002023-08-02T19:37:39.596+02:00440 Torus-Opposite Pairs of the 880 Frénicle Magic Squares of Order-4<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3eKt5lCXm6U54cPJMlmfHFO7nUHqByaukJGOPoFJjDeEuQA0kfU3QRVLN8hTCvFIbD-E2oLrPhtfEC4wepTkvL1lIGA9_dfLwYXDOXCVSHfR4IN0ism9M2dgjTloJdBzhprSwt4yn0i26hhkUH7oBWwnPgxah3Miv1Bo9NFw05IYzC3gteodU3YPH/s797/Tesseract_torus_og.png"><img data-original-height="418" data-original-width="797" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3eKt5lCXm6U54cPJMlmfHFO7nUHqByaukJGOPoFJjDeEuQA0kfU3QRVLN8hTCvFIbD-E2oLrPhtfEC4wepTkvL1lIGA9_dfLwYXDOXCVSHfR4IN0ism9M2dgjTloJdBzhprSwt4yn0i26hhkUH7oBWwnPgxah3Miv1Bo9NFw05IYzC3gteodU3YPH/s320/Tesseract_torus_og.png" style="display: none;" /></a>
<h3 style="text-align: justify;">Finding the torus-opposite pairs of magic squares in even-orders:</h3>
<p style="text-align: justify;">The following diagram, which<i> </i>illustrates the array of <i>n²</i> essentially-different square viewpoints of a basic magic torus of order-<i>n</i>, starting here with the 4x4 magic square that has the Frénicle index n° 1, shows how a torus-opposite magic square of order-4 can be identified:</p>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGirICNGD-09WN60OXSwebFda1jA-wy_TMW23guIhRB2MdTLuwcBvDiOB1gRcmUMy8PyvkzaogVp7-n1X38itIJFc_CTmnPceU_xAnNxTfdfOeFRUioIUsranyJbD7TBKJO1p98ZGQ2xHbK4TRIJj7JFsI7KQkUdS7_bfj0WqPry_7lHdEpBXl9BpN/s2636/Array-of-magic-squares-of-a-basic-magic-torus-of-order-4.png" style="margin-left: auto; margin-right: auto;"><img alt="This diagram shows how to identify a torus-opposite magic square in order-4. The method can be applied to all even-orders." border="0" data-original-height="2636" data-original-width="2536" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGirICNGD-09WN60OXSwebFda1jA-wy_TMW23guIhRB2MdTLuwcBvDiOB1gRcmUMy8PyvkzaogVp7-n1X38itIJFc_CTmnPceU_xAnNxTfdfOeFRUioIUsranyJbD7TBKJO1p98ZGQ2xHbK4TRIJj7JFsI7KQkUdS7_bfj0WqPry_7lHdEpBXl9BpN/w385-h400/Array-of-magic-squares-of-a-basic-magic-torus-of-order-4.png" title="Array of 16 essentially-different square viewpoints of a basic magic torus of order-4" width="385" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Array of 16 essentially-different square viewpoints of a basic magic torus of order-4</span></td></tr></tbody></table>
<p style="text-align: justify;">This basic magic torus, now designated as type n° T4.05.1.01, can be seen to display a torus-opposite pair of <a href="https://carresmagiques.blogspot.com/2019/09/list-of-880-Frenicle-magic-squares-of-order-4.html" target="_blank">Frénicle-indexed magic squares</a> n° 1-458 <a href="https://archive.org/details/AmusementsInMathematicspdf/page/n175/mode/2up?" target="_blank">(with Dudeney pattern VI)</a>, as well as 7 torus-opposite pairs of semi-magic squares that the discerning reader will easily be able to spot.</p>
<p style="text-align: justify;">The relative positions of the numbers of torus-opposite squares can be expressed by a simple plus or minus vector. There are always two equal shortest paths towards the far side of the torus: These are, in toroidal directions, east or west along the latitudes, and in poloidal directions, north or south along the longitudes of the doubly-curved 2D surface. So, if the even-order is <i>n</i>, then:</p>
<p style="text-align: center;"><i><b>v</b> = ( ± n/2, ± n/2 )</i></p>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdwXEp4km0Z-XRa1wIt6hhEbLeMnOyYoqd1Wj5DsISc9PHiBWO_m-uqGS6PXT-DggODE0SFDQJLTqz2X_e7bGvS4SfgR_s6vg7blZ3IsQwz5NpY6TWOME-sKFbwF3oHn9vxJ0f8vOUboCcp5bi0U-2DP2AJNOF2cFB4cpmtJZD_XujdPHfS5__NG2D/s4000/Tesseract_torus.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2680" data-original-width="4000" height="214" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdwXEp4km0Z-XRa1wIt6hhEbLeMnOyYoqd1Wj5DsISc9PHiBWO_m-uqGS6PXT-DggODE0SFDQJLTqz2X_e7bGvS4SfgR_s6vg7blZ3IsQwz5NpY6TWOME-sKFbwF3oHn9vxJ0f8vOUboCcp5bi0U-2DP2AJNOF2cFB4cpmtJZD_XujdPHfS5__NG2D/s320/Tesseract_torus.png" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">"Tesseract Torus" by Tilman Piesk CC-BY-4.0</span><span style="font-size: xx-small;"><br /> https://commons.wikimedia.org/w/index.php?curid=101975795</span></td></tr></tbody></table>
<p style="text-align: justify;">Torus-opposite squares are not just limited to basic magic tori, as they also exist on pandiagonal, semi-pandiagonal, partially pandiagonal, and even semi-magic tori of even-orders. Therefore, for order-4, we can either say that there are 880 magic squares, or we can announce that there are 440 torus-opposite pairs of magic squares. Similarly, the <a href="https://oeis.org/A271103" target="_blank">67,808 semi-magic squares of order-4</a> can be expressed as 33,904 torus-opposite pairs of semi-magic squares, etc.</p>
<h3 style="text-align: justify;">Why torus-opposite pairs of magic squares cannot exist in odd-orders</h3>
<p style="text-align: justify;">A torus-opposite magic square always exists in even-orders because an even-order magic square has magic diagonals that produce a first magic intersection at a centre <i>between numbers, </i>and another magic intersection at a second centre <i>between numbers</i> on the far side of the torus (at the meeting point of the four corners of the first magic square viewpoint). However, in odd-orders, where a magic square has magic diagonals that produce a magic intersection <i>over a number</i>, then a sterile <i>non-magic intersection</i> always occurs <i>between numbers</i> on the far side of the torus (at the meeting point of the four corners of the initial magic square). This is why torus-opposite pairs of magic squares cannot exist in the odd-orders.</p>
<h3 style="text-align: justify;">255 magic tori of order-4, listed by type, with details of the 440 torus-opposite pairs of the 880 Frénicle magic squares of order-4</h3>
<p style="text-align: justify;">The enumeration of the 255 magic tori of order-4 was first published in French on the 28th October 2011, before being translated into English on the 9th January 2012: <a href="https://carresmagiques.blogspot.com/2012/01/255-fourth-order-magic-tori-and-1-third.html" target="_blank">"255 Fourth-Order Magic Tori, and 1 Third-Order Magic Torus."</a> In this previous article, the corresponding 880 fourth-order magic squares were listed by their Frénicle index numbers, but not always illustrated. The intention of the enclosed paper is therefore to facilitate the understanding of the magic tori of order-4, by portraying each case.</p>
<p style="text-align: justify;">Here, Frénicle index numbers continue to be used, as they have the double advantage of being both well known and commonly accepted for cross-reference purposes. But please also note, that now, in order to simplify the visualisation of the magic tori, their displayed magic squares are not systematically presented in Frénicle standard form. </p><p style="text-align: justify;">In the illustrations of the 255 magic tori of order-4, listed by type with the presentation of their magic squares, the latter are labelled from left to right with their Frénicle index number, followed by, in brackets, the Frénicle index number of their torus-opposite magic square, and finally by the Roman numeral of their Dudeney complementary number pattern. Therefore, for the magic square of order-4 with Frénicle index n° 1 (that forms a torus-opposite pair of magic squares with Frénicle index n° 458; both squares having the same Dudeney pattern VI), its label is 1 (458) VI.</p><p style="text-align: justify;">To find the <a href="https://drive.google.com/file/d/17asBnJs37_vppOmR6_shxhRSZjh-YIz0/view?usp=drive_link" target="_blank">"255 magic tori of order-4, listed by type, with details of the 440 torus-opposite pairs of the 880 Frénicle magic squares of order-4"</a> please consult the following PDF:</p>
<iframe allow="autoplay" height="717" src="https://drive.google.com/file/d/17asBnJs37_vppOmR6_shxhRSZjh-YIz0/preview" width="518"></iframe>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-21305205906721481682022-06-07T22:41:00.027+02:002023-06-19T22:53:02.217+02:00Polyomino Area Magic Tori<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjN_NrUN4qYWK0LVCZTb-PmcemEgfoHvMpZD_myulIYTFYjRLj-bjKSMm4VpcGbXy3yhpf5zeMH3YXRc6Va3yfHRoHMjb5TTfYJHCIhdNvGX6wQMgSSo21guTzdkDHl41a9WebImP5B-gpeWoU-dy8tCG6RQ8PdgrMyQzcA6lhr8NgF87GbDgH8MgQ5/s800/W_og_PAMT_ord-3_sums_15_tet.png"><img data-original-height="419" data-original-width="800" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjN_NrUN4qYWK0LVCZTb-PmcemEgfoHvMpZD_myulIYTFYjRLj-bjKSMm4VpcGbXy3yhpf5zeMH3YXRc6Va3yfHRoHMjb5TTfYJHCIhdNvGX6wQMgSSo21guTzdkDHl41a9WebImP5B-gpeWoU-dy8tCG6RQ8PdgrMyQzcA6lhr8NgF87GbDgH8MgQ5/s320/W_og_PAMT_ord-3_sums_15_tet.png" style="display: none;" /></a>
<p style="text-align: justify;">A magic torus can be found with any <a href="https://en.wikipedia.org/wiki/Magic_square" target="_blank">magic square</a>, as has already been demonstrated in the article <a href="https://carresmagiques.blogspot.com/2020/04/from-magic-square-to-magic-torus.html" target="_blank">"From the Magic Square to the Magic Torus"</a>. In fact, there are n^2 essentially different <a href="https://en.wikipedia.org/wiki/Magic_square#Classification_of_magic_squares" target="_blank">semi-magic</a> or magic squares, displayed by every magic torus of order-n. Particularly interesting to observe with <a href="https://carresmagiques.blogspot.com/2012/12/fourth-order-panmagic-torus-t4194.html" target="_blank">pandiagonal (or panmagic)</a> examples, a magic torus can easily be represented by repeating the number cells of one of its magic square viewpoints outside its limits. However, once we begin to look at <a href="https://carresmagiques.blogspot.com/2020/04/area-magic-squares-and-tori-of-order-3.html" target="_blank"><i>area </i>magic squares</a>, it becomes much less evident to visualise and construct the corresponding <i>area </i>magic tori using repeatable<i> area</i> cells, especially when the latter have to be irregular quadrilaterals... The following illustration shows a sketch of an area magic torus of order-3 that I created back in January 2017. I call it a sketch because it may be necessary to use consecutive areas starting from 2 or from 3, should the construction of an area magic torus of order-3, using consecutive areas from 1 to 9, prove to be impossible. And while it can be seen that such a torus is theoretically constructible, many calculations will be necessary to ensure that the areas are accurate, and that the irregular quadrilateral cells can be assembled with precision:</p>
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhcZijlwwyTNhiFQjljWwQtHuFBpm0wvFx8xD3CxemorNx2kh1d_ujuEkGfUPjwuNIi-kIQYLe_VDf_DPFbeecmv3ZlSW4UZEh3LMRGIefvx_t5KIJEhiVeTBbI1FzNOB5Cip9h5f0OxLH0zV-kaDqM9Y6BuKwO_R2_e_LAuahUOY0_-xTr-mysyJ_l/s4666/area_magic_torus_quadrilaterals_WW_20170106.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Colour diagram of an area magic torus of order-3, showing the 9 magic square viewpoints, created by William Walkington in 2017" border="0" data-original-height="4666" data-original-width="4402" height="423" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhcZijlwwyTNhiFQjljWwQtHuFBpm0wvFx8xD3CxemorNx2kh1d_ujuEkGfUPjwuNIi-kIQYLe_VDf_DPFbeecmv3ZlSW4UZEh3LMRGIefvx_t5KIJEhiVeTBbI1FzNOB5Cip9h5f0OxLH0zV-kaDqM9Y6BuKwO_R2_e_LAuahUOY0_-xTr-mysyJ_l/w605-h640/area_magic_torus_quadrilaterals_WW_20170106.png" title="Area Magic Torus of Order-3 by William Walkington" width="400" /></a></div>
<p style="text-align: justify;">At the time discouraged by the complications of such geometries, I decided to suspend the research of area magic tori. But since the invention of area magic squares, other authors have introduced some very interesting <a href="https://en.wikipedia.org/wiki/Polyomino" target="_blank">polyomino</a> versions that open new perspectives: </p><div style="text-align: justify;">On the 20th May 2021, <a href="https://twitter.com/nosiika/status/1395488284151738368/photo/1" target="_blank">Morita Mizusumashi</a> (盛田みずすまし
@nosiika) tweeted a nice <a href="https://twitter.com/nosiika/status/1395488284151738368/photo/1" target="_blank">polyomino area magic square of order-3</a> constructed with 9 assemblies of <i>5</i> to <i>13</i> monominoes. On the 21st May 2021, <a href="https://www.researchgate.net/profile/Yoshiaki-Araki" target="_blank">Yoshiaki Araki</a> (面積魔方陣がテセレーションみたいな件
@alytile) tweeted several order-4 and order-3 solutions in <a href="https://twitter.com/alytile/status/1395611974390542337/photo/1" target="_blank">a polyomino area magic square thread</a>. These included (amongst others) an order-4 example constructed with 16 assemblies of 5 to 20 <a href="https://en.wikipedia.org/wiki/Domino_(mathematics)" target="_blank">dominoes</a>. On the 24th May 2021, Yoshiaki Araki then tweeted <a href="https://twitter.com/alytile/status/1396758907582779397/photo/1" target="_blank">an order-3 polyomino area magic square</a> constructed using 9 assemblies of 1 to 9 same-shaped <a href="https://en.wikipedia.org/wiki/Pentomino" target="_blank">pentominoes</a><a href="https://en.wikipedia.org/wiki/Pentomino" target="_blank">!</a> <a href="https://www.cs.purdue.edu/homes/gnf/book/Booknews/edoscub7.html" target="_blank">Edo Timmermans</a>, the author of this beautiful square, had apparently been inspired by Yoshiaki Araki's previous posts! Since the 22nd June 2021, <a href="https://inderjtaneja.com/" target="_blank">Inder Taneja</a> has also published a paper entitled <a href="https://zenodo.org/record/5009224" target="_blank">"Creative Magic Squares: Area Representations"</a> in which he studies polyomino area magic using perfect square magic sums.</div><p></p>
<h3 style="text-align: justify;">Intention and Definition</h3>
<p style="text-align: justify;">The intention of the present article is to explore the use of
polyominoes for area magic torus construction, with the objective of facilitating the calculation
and verification of the cell areas, while avoiding the geometric constraints of irregular quadrilateral assemblies. Here, it is useful to give a definition of a polyomino area magic torus:</p><div style="text-align: justify;"></div>
<blockquote><div style="text-align: justify;">1/ In the diagram of the torus, the entries of the cells of each column, row, and of at least two intersecting diagonals, will add up to the same magic sum. The intersecting magic diagonals can be offset or <a href="https://en.wikipedia.org/wiki/Broken_diagonal" target="_blank">broken</a>, as the area magic torus has a limitless surface, and can therefore display <a href="https://en.wikipedia.org/wiki/Magic_square#Classification_of_magic_squares" target="_blank">semi-magic square</a> viewpoints.</div><div style="text-align: justify;"> 2/ Each cell will have an area in proportion to its number. The different areas will be represented by tiling with same-shaped holeless polyominoes.</div>
<div style="text-align: justify;">
3/ The cells can be of any regular or irregular rectangular shape that results from their holeless tiling. </div><div style="text-align: justify;">4/ Depending on the order-n of the area magic torus, each cell will have continuous edge connections with contiguous cells (and these connections can be wrap-around, <a href="https://carresmagiques.blogspot.com/2020/04/from-magic-square-to-magic-torus.html" target="_blank">because the torus diagram represents a limitless curved surface</a>).<br /></div>
<div style="text-align: justify;">5/ The vertex meeting points of four cells can only take place at four convex (i.e. 270° exterior angled) vertices of each of the cells.</div></blockquote>
<h3 style="text-align: left;">Polyomino Area Magic Tori (PAMT) of Order-3</h3>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgST5oz5HfyUZrCgO_2ioFw1nTFMtGsFkcpK_FHKoFKzlLRJuZMbF3VU7IzeCZnzLohbfqgEZlIYF4ufeV6KIoIBjVhZhQwR2-Ic7sel9OCCpHshfuHttBMGwA0JYK6LmCT7A-0pqjI-Ilg-nw_94dIoCq-7t8Pz_369a-7IMaWTKRs3agIibagpeus/s1976/W_MT_ord-3_sums_15.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of the magic torus of order-3, displaying Agrippa's "Saturn" magic square, with graphics by William Walkington" border="0" data-original-height="1976" data-original-width="1964" height="125" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgST5oz5HfyUZrCgO_2ioFw1nTFMtGsFkcpK_FHKoFKzlLRJuZMbF3VU7IzeCZnzLohbfqgEZlIYF4ufeV6KIoIBjVhZhQwR2-Ic7sel9OCCpHshfuHttBMGwA0JYK6LmCT7A-0pqjI-Ilg-nw_94dIoCq-7t8Pz_369a-7IMaWTKRs3agIibagpeus/w199-h200/W_MT_ord-3_sums_15.png" title="Magic Torus index n° T3, of order-3. Magic sums = 15." width="125" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Magic Torus index n° T3, of order-3. Magic sums = 15.<br /><i>Please note that this is not a Polyomino Area Magic Torus,</i><br />but it is the <a href="https://archive.org/details/DeOccultaPhilosophiaLoc1533/page/n163/mode/2up" target="_blank">Agrippa "Saturn" magic square</a>, after a rotation of +90°, in <a href="https://en.wikipedia.org/wiki/Fr%C3%A9nicle_standard_form" target="_blank">Frénicle standard form</a>.</td></tr></tbody></table>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWdWZdWZjrfEwwEoNMCVOZEomB4Pwr90XIBDI7TblK9_JjoPuSTbMvv_m1xYmEiwspNAmHfoOVXjgMYLquT_AXDPuTaKgTGA8rJj7YN2O95pWMH4bB7XJ44I6HtOntjsR12cUTx0GCth6mKeBvBOJ6xuO4APsNkGrF1agU9KfnB4GbUlEiZ3qdV86I/s5734/W_PAMT_ord-3_sums_15_tetrominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Diagram of irregular rectangular Polyomino Area Magic Torus of order-3 with tetromino tiles, by William Walkington in 2022" border="0" data-original-height="3712" data-original-width="5734" height="227" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWdWZdWZjrfEwwEoNMCVOZEomB4Pwr90XIBDI7TblK9_JjoPuSTbMvv_m1xYmEiwspNAmHfoOVXjgMYLquT_AXDPuTaKgTGA8rJj7YN2O95pWMH4bB7XJ44I6HtOntjsR12cUTx0GCth6mKeBvBOJ6xuO4APsNkGrF1agU9KfnB4GbUlEiZ3qdV86I/w400-h259/W_PAMT_ord-3_sums_15_tetrominoes.png" title="Polyomino Area Magic Torus (PAMT) of order-3. Magic sums = 15. Tetrominoes." width="350" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Polyomino Area Magic Torus (PAMT) of order-3. Magic sums = 15. <a href="https://en.wikipedia.org/wiki/Tetromino" target="_blank">Tetrominoes</a>.<br />Consecutively numbered areas 1 to 9, in an irregular rectangular shape of 180 units.</td></tr></tbody></table>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAAmN7Sg8r_hgUbVDn4P6fCp0fpJEW9mtVHtXY1eQDfA5AypiPmEEL74gyMY9uCAFcRb3oU9KUEboB7xw7rmqkYZQG12zj6xZDS7xHXGN84IoI4ajYhxeZPDm_bUFX4kIR-tHVF17hdMWGWq40UUCFMN8wmSZIaHsBihI5QF0nifiL78mqi8rNdFgX/s4462/W_PAMT_ord-3_sums_18_trominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Diagram of an irregular rectangular Polyomino Area Magic Torus of order-3 with tromino tiles, by William Walkington in 2022" border="0" data-original-height="4462" data-original-width="3048" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAAmN7Sg8r_hgUbVDn4P6fCp0fpJEW9mtVHtXY1eQDfA5AypiPmEEL74gyMY9uCAFcRb3oU9KUEboB7xw7rmqkYZQG12zj6xZDS7xHXGN84IoI4ajYhxeZPDm_bUFX4kIR-tHVF17hdMWGWq40UUCFMN8wmSZIaHsBihI5QF0nifiL78mqi8rNdFgX/w219-h320/W_PAMT_ord-3_sums_18_trominoes.png" title="Polyomino Area Magic Torus (PAMT) of Order-3. Magic sums = 18. Trominoes." width="219" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Polyomino Area Magic Torus (PAMT) of Order-3. Magic sums = 18. <a href="https://en.wikipedia.org/wiki/Tromino" target="_blank">Trominoes</a>.<br />Consecutively numbered areas 2 to 10, in an irregular rectangular shape of 162 units.</td></tr></tbody></table>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiTl_nZqSOTDBP4219J60hBjNNfSVD89x3NDvqMNN966yAWDqxXKwK8v_iiV4Tw_C0VLgSmfL98EJg8jo8cSH3EJ7iH1z2KHHwwXoH2kjQLtX-Y2gi8mzsc5YVvyAfODTh8FN9UcX4XJfBW-bDzGjlu3dT4FzC7Rhz-z8MY5SM6IyHkKA8p02WiC2ri/s4590/W_PAMT_ord-3_sums_24_trominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of an oblong Polyomino Area Magic Torus of order-3 with tromino tiles, created by William Walkington in 2022" border="0" data-original-height="4590" data-original-width="3141" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiTl_nZqSOTDBP4219J60hBjNNfSVD89x3NDvqMNN966yAWDqxXKwK8v_iiV4Tw_C0VLgSmfL98EJg8jo8cSH3EJ7iH1z2KHHwwXoH2kjQLtX-Y2gi8mzsc5YVvyAfODTh8FN9UcX4XJfBW-bDzGjlu3dT4FzC7Rhz-z8MY5SM6IyHkKA8p02WiC2ri/w219-h320/W_PAMT_ord-3_sums_24_trominoes.png" title="Polyomino Area Magic Torus (PAMT) of order-3. Magic sums = 24. Trominoes." width="219" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Polyomino Area Magic Torus (PAMT) of order-3. Magic sums = 24. <a href="https://en.wikipedia.org/wiki/Tromino" target="_blank">Trominoes</a>.<br />Consecutively numbered areas 4 to 12, in an oblong 12 ⋅ 18 = 216 units.</td></tr></tbody></table><p>
</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhwHuf8UyBimYz5AlaOcxTjAiU7Ao1evq2sPZsq-25RLiH25qdMJgbHjLtF2FMR8RO2yU58xhAB6ECVR4I7b6eOpaqILOotIn76ETjsXa4qRBDdKSfbGC17-VMKOdOzDyXE_zSB49E-7Cv_NsMtwcQlNtgws87d_m_JDPRGcjmeNzq-ksDP6lZxlaZ2/s4468/W_PAMT_ord-3_sums_36_V1_trominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a square Polyomino Area Magic Torus of order-3 with tromino tiles, V1 created by William Walkington in 2022" border="0" data-original-height="4468" data-original-width="4462" height="219" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhwHuf8UyBimYz5AlaOcxTjAiU7Ao1evq2sPZsq-25RLiH25qdMJgbHjLtF2FMR8RO2yU58xhAB6ECVR4I7b6eOpaqILOotIn76ETjsXa4qRBDdKSfbGC17-VMKOdOzDyXE_zSB49E-7Cv_NsMtwcQlNtgws87d_m_JDPRGcjmeNzq-ksDP6lZxlaZ2/s320/W_PAMT_ord-3_sums_36_V1_trominoes.png" title="Polyomino Area Magic Torus (PAMT) of Order-3. Magic sums = 36. Trominoes V1." width="219" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Polyomino Area Magic Torus (PAMT) of Order-3. Magic sums = 36. <a href="https://en.wikipedia.org/wiki/Tromino" target="_blank">Trominoes</a> Version 1.<br />Square 18 ⋅ 18 = 324 units.</td></tr></tbody></table>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiIbfyPgJu3GDG7Vre5URSBP-DtVRGecky5ORt3MNh91Bjpbawvrd3yv3YyZ9pslY12EE3Q3Iwh87kfV1P8lmS15JhkNg0Dpmbdi51gccmuQ99mIg5UHQpr0egbWu4KbhO9PTRux7GVsHMpHvlfvimDgNHV2eAa3JCcTktUeWOa9iwTmWl0n3SU2YhV/s4468/W_PAMT_ord-3_sums_36_V2_trominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a square Polyomino Area Magic Torus of order-3 with tromino tiles, V2 created by William Walkington in 2022" border="0" data-original-height="4456" data-original-width="4468" height="219" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiIbfyPgJu3GDG7Vre5URSBP-DtVRGecky5ORt3MNh91Bjpbawvrd3yv3YyZ9pslY12EE3Q3Iwh87kfV1P8lmS15JhkNg0Dpmbdi51gccmuQ99mIg5UHQpr0egbWu4KbhO9PTRux7GVsHMpHvlfvimDgNHV2eAa3JCcTktUeWOa9iwTmWl0n3SU2YhV/w320-h319/W_PAMT_ord-3_sums_36_V2_trominoes.png" title="Polyomino Area Magic Torus (PAMT) of Order-3. Magic sums = 36. Trominoes Version 2." width="219" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Polyomino Area Magic Torus (PAMT) of Order-3. Magic sums = 36. <a href="https://en.wikipedia.org/wiki/Tromino" target="_blank">Trominoes</a> Version 2.<br />Square 18 ⋅ 18 = 324 units.</td></tr></tbody></table>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPG8zfZsO9Kwn2Um3dsX8hLlBP6Ot7qoYYRcssCAa6nyEhlwIFyfblYL6g_SvsdMNYWaCX0ViYE-0X4cAmb2YRCgPfM9af5cKinbIfpgEnuekbZIRrTEi96e1g-5UmQgDPKbK03tQnW2M5gMZX9ntkTohryqkRQong5hhuUOZGggu0I_HPgOHC15eh/s4570/W_PAMT_Ord-3_sums_60_V1_pentominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a square Polyomino Area Magic Torus of order-3 with pentomino tiles, V1 created by William Walkington in 2022" border="0" data-original-height="4570" data-original-width="4564" height="219" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPG8zfZsO9Kwn2Um3dsX8hLlBP6Ot7qoYYRcssCAa6nyEhlwIFyfblYL6g_SvsdMNYWaCX0ViYE-0X4cAmb2YRCgPfM9af5cKinbIfpgEnuekbZIRrTEi96e1g-5UmQgDPKbK03tQnW2M5gMZX9ntkTohryqkRQong5hhuUOZGggu0I_HPgOHC15eh/w320-h320/W_PAMT_Ord-3_sums_60_V1_pentominoes.png" title="Polyomino Area Magic Torus (PAMT) of Order-3. Magic sums = 60. Pentominoes Version 1." width="219" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Polyomino Area Magic Torus (PAMT) of Order-3. Magic sums = 60. <a href="https://en.wikipedia.org/wiki/Pentomino" target="_blank">Pentominoes</a> Version 1.<br />Square 30 ⋅ 30 = 900 units.</td></tr></tbody></table>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7n93-8qJqmdo0qpA7WZFiZTt_gCsmYKMcWWbWj8DqVRhmV-Vi31HthLtR6g4GqpjBkoe8oom4ZumE2UlWIZcqREcOL1Z9wrYEOo0EB68VfXn3K80ynUKg7z_3XeR5yk_0YRQX18rq9KgFFuCnfnb0rXLOwLJAEvzoj_O237y7_EObRBwUV8o9kEfR/s4444/W_PAMT_ord-3_sums_24_V1_monominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Diagram of an irregular rectangular Polyomino Area Magic Torus of order-3 with monomino tiles, by William Walkington in 2022" border="0" data-original-height="4438" data-original-width="4444" height="219" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7n93-8qJqmdo0qpA7WZFiZTt_gCsmYKMcWWbWj8DqVRhmV-Vi31HthLtR6g4GqpjBkoe8oom4ZumE2UlWIZcqREcOL1Z9wrYEOo0EB68VfXn3K80ynUKg7z_3XeR5yk_0YRQX18rq9KgFFuCnfnb0rXLOwLJAEvzoj_O237y7_EObRBwUV8o9kEfR/w320-h320/W_PAMT_ord-3_sums_24_V1_monominoes.png" title="Polyomino Area Magic Torus (PAMT) of order-3. Magic sums = 24. Monominoes." width="219" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Polyomino Area Magic Torus (PAMT) of order-3. Magic sums = 24. <a href="https://en.wikipedia.org/wiki/Polyomino" target="_blank">Monominoes</a>.<br />Consecutively numbered areas 4 to 12, in an irregular rectangular shape of 72 units.</td></tr></tbody></table>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2OB6slzeYIN7XHgGljgfETcEt97Q5dPutq1hP7nZOMVwdNPZj3J_cm6nHN57-cNWw0U4J6jlGKamE-1C8BeNH2Q1ijwj3Q1mEH-zT78Pl_cp6WXoz7cN7zS2jY4SxZ1Md9DMWdfFGtIMOqLyd75Xk4M0jEvHOOBjjSm82YaHghSuTDsMTtQ-YWp3O/s4366/W_PAMT_ord-3_sums_27_V1_monominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a square Polyomino Area Magic Torus of order-3 with monomino tiles, V1 created by William Walkington in 2022" border="0" data-original-height="4366" data-original-width="4354" height="219" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2OB6slzeYIN7XHgGljgfETcEt97Q5dPutq1hP7nZOMVwdNPZj3J_cm6nHN57-cNWw0U4J6jlGKamE-1C8BeNH2Q1ijwj3Q1mEH-zT78Pl_cp6WXoz7cN7zS2jY4SxZ1Md9DMWdfFGtIMOqLyd75Xk4M0jEvHOOBjjSm82YaHghSuTDsMTtQ-YWp3O/w319-h320/W_PAMT_ord-3_sums_27_V1_monominoes.png" title="Polyomino Area Magic Torus (PAMT) of order-3. Magic sums = 27. Monominoes Version 1." width="219" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Polyomino Area Magic Torus (PAMT) of order-3. Magic sums = 27. <a href="https://en.wikipedia.org/wiki/Polyomino" target="_blank">Monominoes</a> Version 1.<br />Consecutively numbered areas 5 to 13, in a square 9 ⋅ 9 = 81 units.</td></tr></tbody></table>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi89HA920-8psHy_2DoXV5tTk7SO1eYLyNQXT2OlXp7jxZTmaPnfa4ffTljcytQ_U-GclqlBs3Bf9_QMMxVk36E6V_IiJH_JIUoI-KN_ad7w_tmGII3kTEiBjc4EQALybu573XURddDxblIgvz_sThUQ0EqooKszCA8sOGQ3sX7kl_wZ3Of6kNsZi1n/s4356/W_PAMT_ord-3_sums_27_V2_monominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a square Polyomino Area Magic Torus of order-3 with monomino tiles, V2 created by William Walkington in 2022" border="0" data-original-height="4354" data-original-width="4356" height="219" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi89HA920-8psHy_2DoXV5tTk7SO1eYLyNQXT2OlXp7jxZTmaPnfa4ffTljcytQ_U-GclqlBs3Bf9_QMMxVk36E6V_IiJH_JIUoI-KN_ad7w_tmGII3kTEiBjc4EQALybu573XURddDxblIgvz_sThUQ0EqooKszCA8sOGQ3sX7kl_wZ3Of6kNsZi1n/s320/W_PAMT_ord-3_sums_27_V2_monominoes.png" title="Polyomino Area Magic Torus (PAMT) of order-3. Sums = 27. Monominoes Version 2." width="219" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Polyomino Area Magic Torus (PAMT) of order-3. Magic sums = 27. <a href="https://en.wikipedia.org/wiki/Polyomino" target="_blank">Monominoes</a> Version 2.<br />Consecutively numbered areas 5 to 13, in a square 9 ⋅ 9 = 81 units.</td></tr></tbody></table>
<br />
<h3 style="text-align: left;">Polyomino Area Magic Tori (PAMT) of Order-4</h3>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_h73uA19TWS-cm8mZ44qF6Zc7OhaibnWKPryXXJgzcutZ_-Dre1V2IVnzclipB14KsywSMcI6NpuZFXoSjUqFHJblTwSESzKUyCRPevodaE_G7T61Tx9HPh7qwtQNviuAUW5BJKfohzjcRZbxED07GbYnggwUXcZvbVsC1QTp4ul7VGAQ-3Wu-S8q/s1672/W_MT_Ord-4_pand_sums_34_V1_16_Frenicle.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a pandiagonal Magic Torus of order-4, displaying the Frénicle 107 index number square, by William Walkington" border="0" data-original-height="1672" data-original-width="1669" height="125" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_h73uA19TWS-cm8mZ44qF6Zc7OhaibnWKPryXXJgzcutZ_-Dre1V2IVnzclipB14KsywSMcI6NpuZFXoSjUqFHJblTwSESzKUyCRPevodaE_G7T61Tx9HPh7qwtQNviuAUW5BJKfohzjcRZbxED07GbYnggwUXcZvbVsC1QTp4ul7VGAQ-3Wu-S8q/w199-h200/W_MT_Ord-4_pand_sums_34_V1_16_Frenicle.png" title="Magic Torus index n° T4.198, of order-4. Magic sums = 34." width="125" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><a href="https://carresmagiques.blogspot.com/2020/04/table-of-fourth-order-magic-tori.html" target="_blank">Magic Torus index n° T4.198</a>, of order-4. Magic sums = 34.<br /><i>Please note that this is not a Polyomino Area Magic Torus,</i><br />but it is a pandiagonal torus represented by a pandiagonal square that has <a href="https://carresmagiques.blogspot.com/2020/04/list-of-880-Frenicle-magic-squares-of-order-4.html" target="_blank">Frénicle index n° 107</a>.<br /></td></tr></tbody></table><p>The pandiagonal torus above displays 16 <a href="https://carresmagiques.blogspot.com/2020/04/list-of-880-Frenicle-magic-squares-of-order-4.html" target="_blank">Frénicle indexed</a> magic squares n° 107, 109, 171, 204, 292, 294, 355, 396, 469, 532, 560, 621, 691, 744, 788, and 839. It is entirely covered by <a href="https://carresmagiques.blogspot.com/2013/03/1920-sub-magic-squares-on-255-4th-order.html" target="_blank">16 sub-magic 2x2 squares</a>. The torus is <a href="https://carresmagiques.blogspot.com/2020/04/self-complementary-magic-tori-order-4.html" target="_blank">self-complementary and has the magic torus complementary number pattern I</a>. <a href="https://carresmagiques.blogspot.com/2020/04/even-and-odd-number-patterns-on-magic-tori.html" target="_blank">The even-odd number pattern is P4.1</a>. This torus is <a href="https://carresmagiques.blogspot.com/2020/04/extra-magic-tori-and-knight-move-magic-diagonals.html" target="_blank">extra-magic with 16 extra-magic nodal intersections of 4 magic lines</a>.
It displays pandiagonal <a href="https://archive.org/details/AmusementsInMathematicspdf/page/n175/mode/2up?view=theater&q=Magic+square+problems" target="_blank">Dudeney I Nasik magic squares</a>. It is classified with a <a href="https://carresmagiques.blogspot.com/2020/04/table-of-fourth-order-magic-tori.html" target="_blank">Magic Torus index n° T4.198</a>,
and is of <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">Magic Torus type n° T4.01.2</a>. Also, when compared with its two pandiagonal torus cousins of order-4, the <i>unique</i> Magic Torus T4.198 of the <a href="https://carresmagiques.blogspot.com/2020/04/multiplicative-magic-tori-and-magic-squares.html" target="_blank">Multiplicative Magic Torus MMT4.01.1</a> is distinguished by its total <i>self-complementarity</i>.<br />
</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7OLikLQ-lOAY-NM-pQ67sKJjjrdvYNKJO_jjOEWrDr6P37Jz8X_KxHiH05RxCy0Il472Hr64SuowqOh5NG3SGqklaLFQ40p1pg3fYlpGD340xbW0sXTtGVxYHo6TjdUsqUf4n9KqEazaQYUKy9UXzxz_L3tUvYflmKFSIQgGw456jYIqh1jSggJvE/s6560/W_PAMT_Ord-4_pand_sums_34_V1_view_1_16.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a pandiagonal Polyomino Area Magic Torus of order-4, constructed with pentominoes by William Walkington" border="0" data-original-height="3934" data-original-width="6560" height="255" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7OLikLQ-lOAY-NM-pQ67sKJjjrdvYNKJO_jjOEWrDr6P37Jz8X_KxHiH05RxCy0Il472Hr64SuowqOh5NG3SGqklaLFQ40p1pg3fYlpGD340xbW0sXTtGVxYHo6TjdUsqUf4n9KqEazaQYUKy9UXzxz_L3tUvYflmKFSIQgGw456jYIqh1jSggJvE/w640-h384/W_PAMT_Ord-4_pand_sums_34_V1_view_1_16.png" title="Polyomino Area Magic Torus (PAMT) of order-4. Magic sums = 34. Pentominoes." width="425" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Pandiagonal Polyomino Area Magic Torus (PAMT) of order-4. Magic sums = 34. <a href="https://en.wikipedia.org/wiki/Pentomino" target="_blank">Pentominoes</a>.<br />Index PAMT4.198, Version 1, Viewpoint 1/16, displaying <a href="https://carresmagiques.blogspot.com/2020/04/list-of-880-Frenicle-magic-squares-of-order-4.html" target="_blank">Frénicle magic square index n° 107.</a> <br />Consecutively numbered areas 1 to 16, in an oblong 34 ⋅ 20 = 680 units. </td></tr></tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKy0eKOuZ8B37kmCQfDrYcG69WHm_n_97LCamCrQOzHjVSksZCib4WhEB6jWL9ZkYTzsMJinu8vIwBb51ZkN7mjiGmdneQHXTA7uww5PHSZUwJa0jYSEvybndGijbmkFpZUfmDTjALMY9rxLMnTuviRinEalO6pWVjLxIugWIGESCdELyrVDdXA1SJ/s4426/W_PAMT_Ord-4_pand_sums_50_V1_view_1_16.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a square Polyomino Area Magic Torus of order-4 with domino tiles, V1 created by William Walkington in 2022" border="0" data-original-height="4426" data-original-width="4426" height="250" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKy0eKOuZ8B37kmCQfDrYcG69WHm_n_97LCamCrQOzHjVSksZCib4WhEB6jWL9ZkYTzsMJinu8vIwBb51ZkN7mjiGmdneQHXTA7uww5PHSZUwJa0jYSEvybndGijbmkFpZUfmDTjALMY9rxLMnTuviRinEalO6pWVjLxIugWIGESCdELyrVDdXA1SJ/w320-h320/W_PAMT_Ord-4_pand_sums_50_V1_view_1_16.png" title="Pandiagonal Polyomino Area Magic Torus (PAMT) of order-4. Magic sums = 50. Dominoes. Version 1, Viewpoint 1/16." width="250" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Pandiagonal Polyomino Area Magic Torus (PAMT) of order-4. Magic sums = 50. <a href="https://en.wikipedia.org/wiki/Domino_(mathematics)" target="_blank">Dominoes</a>.<br />Version 1, Viewpoint 1/16.<br />Consecutively numbered areas 5 to 20, in a square 20 ⋅ 20 = 400 units.</td></tr></tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJgLpO5Gkm6_WqsuvLKI-EeYL_ponFuKXuPidb57HailPZ06r0g8u56xsqSqzI1cIA86jI3za5c1uOvLRPOnaX3sNPUeOMQikVKHM2NpmKsR-XIPH6GcTnfeqHclaydXD1qQmVONBksrKfj9zLeHpo9AhBbWkOdEQL_DsglBA5r1od9RRErOwAc0Jf/s4171/W_PAMT_Ord-4_pand_sums_50_V1_view_16_16.png" style="margin-left: auto; margin-right: auto;"><img alt="Diagram of an irregularly shaped view of a Polyomino Area Magic Torus of order-4 with domino tiles, by William Walkington in 2022" border="0" data-original-height="4171" data-original-width="3058" height="340" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJgLpO5Gkm6_WqsuvLKI-EeYL_ponFuKXuPidb57HailPZ06r0g8u56xsqSqzI1cIA86jI3za5c1uOvLRPOnaX3sNPUeOMQikVKHM2NpmKsR-XIPH6GcTnfeqHclaydXD1qQmVONBksrKfj9zLeHpo9AhBbWkOdEQL_DsglBA5r1od9RRErOwAc0Jf/w294-h400/W_PAMT_Ord-4_pand_sums_50_V1_view_16_16.png" title="Pandiagonal Polyomino Area Magic Torus (PAMT) of Order-4. Sums = 50. Dominoes. Version 1, Viewpoint 16/16." width="250" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Pandiagonal Polyomino Area Magic Torus (PAMT) of Order-4. Sums = 50. <a href="https://en.wikipedia.org/wiki/Domino_(mathematics)" target="_blank">Dominoes</a>.<br />Version 1, Viewpoint 16/16.<br />Consecutively numbered areas 5 to 20, in an irregular rectangular shape of 400 units.</td></tr></tbody></table>
<br />
<h3 style="text-align: left;">Polyomino Area Magic Tori (PAMT) of Order-5</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhAb7hyHw5ur-fX4defVX7uduYMVRQ7S6ONRXn6gRWyoizEB2xpPzfR7rVBJWjdHNaxltuY5SZxP10GN5oDGVg0USDhBhkYTGr1li7KhmeUaqMOsqeww-Ca3WTQEVsoDfqCkYMDlP5jrKHfgztsOS6t8yhDfK9e6YIY-J925vcx6UoFLxgTul0DtDs/s1036/W_MT_Ord-5_pand_sums_65_V1.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1036" data-original-width="1036" height="156" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhAb7hyHw5ur-fX4defVX7uduYMVRQ7S6ONRXn6gRWyoizEB2xpPzfR7rVBJWjdHNaxltuY5SZxP10GN5oDGVg0USDhBhkYTGr1li7KhmeUaqMOsqeww-Ca3WTQEVsoDfqCkYMDlP5jrKHfgztsOS6t8yhDfK9e6YIY-J925vcx6UoFLxgTul0DtDs/s320/W_MT_Ord-5_pand_sums_65_V1.png" width="156" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Pandiagonal Torus type n° T5.01.00X of order-5. Magic sums = 65.<br /><i>Please note that this is not a Polyomino Area Magic Torus.</i></td></tr></tbody></table>
<p>This pandiagonal torus of order-5 displays 25 pandiagonal magic squares.
It is a direct descendant of the T3 magic torus of order-3, as demonstrated in <a href="https://carresmagiques.blogspot.com/2020/04/magic-torus-coordinate-and-vector.html" target="_blank">page 49 of "Magic Torus Coordinate and Vector Symmetries" (MTCVS)</a>.
In "Extra-Magic Tori and Knight Move Magic Diagonals" it is shown to be an <a href="https://carresmagiques.blogspot.com/2020/04/extra-magic-tori-and-knight-move-magic-diagonals.html" target="_blank">Extra-Magic Pandiagonal Torus Type T5.01 with 6 Knight Move Magic Diagonals</a>. Note that when centred on the number 13, the magic square viewpoint becomes associative. The torus is classed under type n° T5.01.00X (provisional number), and is <a href="https://carresmagiques.blogspot.com/2020/04/251449712-fifth-order-magic-tori.html" target="_blank">one of 144 pandiagonal or panmagic tori type 1 of order-5</a> that display 3,600 pandiagonal or panmagic squares. On page 72 of "Multiplicative Magic Tori" <a href="https://carresmagiques.blogspot.com/2020/04/multiplicative-magic-tori-and-magic-squares.html" target="_blank">it is present within the type MMT5.01.00x</a>.</p>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDCmMGX30R_UxZrF0d7ceShpGNUjkP9k1tKjk5r9lTRjV4anXBerSimJPlsDiL2eCaMgE2bVPSCVVdHeLQmJ3l7KMNX6kt1pJlzvNzob1kVJ1wgGnohcv5CEn318siwZ4bl9Ei1uAdg7e2vxtOxqQfvg9qOMOoxhDt7rrcFgDanV1TlvuSHUinLAtn/s6217/W_PAMT_Ord-5_sums_65_V1_hexominoes_view_1.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a pandiagonal Polyomino Area Magic Torus of order-5, constructed with hexominoes by William Walkington" border="0" data-original-height="2920" data-original-width="6217" height="244" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDCmMGX30R_UxZrF0d7ceShpGNUjkP9k1tKjk5r9lTRjV4anXBerSimJPlsDiL2eCaMgE2bVPSCVVdHeLQmJ3l7KMNX6kt1pJlzvNzob1kVJ1wgGnohcv5CEn318siwZ4bl9Ei1uAdg7e2vxtOxqQfvg9qOMOoxhDt7rrcFgDanV1TlvuSHUinLAtn/w640-h301/W_PAMT_Ord-5_sums_65_V1_hexominoes_view_1.png" title="Pandiagonal Polyomino Area Magic Torus (PAMT) of order-5. Magic sums = 65. Hexominoes. Index PAMT5.01.00X, Version 1, Viewpoint 1/25." width="518" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Pandiagonal Polyomino Area Magic Torus (PAMT) of order-5. Magic sums = 65. <a href="https://en.wikipedia.org/wiki/Hexomino" target="_blank">Hexominoes</a>.<br />Index PAMT5.01.00X, Version 1, Viewpoint 1/25. <br />Consecutively numbered areas 1 to 25, in an oblong 65 ⋅ 30 = 1950 units.</td></tr></tbody></table>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg8tz3okQ7uQLu7pSURzAEyg0jrs0Y2F_SOuZvSrMBuoL-P2R_nGGYxNhWFZGMQ4xz78TA1NVA1hOirpWZNxFuBAQQWFw-yJFmHnsfShqsT2sGqpJB8HIrIymRv3JWsbJouIeJb8RJ_UtbLg4mmXTm8q0iuLOpfnN3ZOP523JK1GYTW0ehgMxXl5F1g/s4376/W_PAMT_Ord-5_sums_125_V21_monominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a square Polyomino Area Magic Torus of order-5 with monomino tiles, V1 created by William Walkington in 2022" border="0" data-original-height="4374" data-original-width="4376" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg8tz3okQ7uQLu7pSURzAEyg0jrs0Y2F_SOuZvSrMBuoL-P2R_nGGYxNhWFZGMQ4xz78TA1NVA1hOirpWZNxFuBAQQWFw-yJFmHnsfShqsT2sGqpJB8HIrIymRv3JWsbJouIeJb8RJ_UtbLg4mmXTm8q0iuLOpfnN3ZOP523JK1GYTW0ehgMxXl5F1g/w320-h320/W_PAMT_Ord-5_sums_125_V21_monominoes.png" title="Pandiagonal Polyomino Area Magic Torus (PAMT) of Order-5. Magic sums = 125. Monominoes. Version 1, Viewpoint 1/25." width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Pandiagonal Polyomino Area Magic Torus (PAMT) of Order-5. Magic sums = 125. <a href="https://en.wikipedia.org/wiki/Polyomino" target="_blank">Monominoes</a>.<br />Version 1, Viewpoint 1/25.<br />Consecutively numbered areas 13 to 37, in a square 25 ⋅ 25 = 625 units.</td></tr></tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUs9anLhCCZFSPcz3IyXaTNmX925Hr93LeqaIRDw6Pxf8xkgi_n-0zsqA9sPIA_IqVaeG7llFXXl6xjmOTXyIHAu7OPHuZd3Y8D47ANvashPKYO4PGHq411rTZ4mGuQxq9sk9hg6uqVlux_tpi1fvdghmMbkSoEcN3AG1-Ml6YOciUdaTimrYIwRyp/s4378/W_PAMT_Ord-5_sums_125_V22_monominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a square Polyomino Area Magic Torus of order-5 with monomino tiles, V2 created by William Walkington in 2022" border="0" data-original-height="4372" data-original-width="4378" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUs9anLhCCZFSPcz3IyXaTNmX925Hr93LeqaIRDw6Pxf8xkgi_n-0zsqA9sPIA_IqVaeG7llFXXl6xjmOTXyIHAu7OPHuZd3Y8D47ANvashPKYO4PGHq411rTZ4mGuQxq9sk9hg6uqVlux_tpi1fvdghmMbkSoEcN3AG1-Ml6YOciUdaTimrYIwRyp/w320-h320/W_PAMT_Ord-5_sums_125_V22_monominoes.png" title="Pandiagonal Polyomino Area Magic Torus (PAMT) of Order-5. Magic sums = 125. Monominoes. Version 2, Viewpoint 1/25." width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Pandiagonal Polyomino Area Magic Torus (PAMT) of Order-5. Magic sums = 125. <a href="https://en.wikipedia.org/wiki/Polyomino" target="_blank">Monominoes</a>.<br />Version 2, Viewpoint 1/25.<br />Consecutively numbered areas 13 to 37, in a square 25 ⋅ 25 = 625 units.</td></tr></tbody></table>
<br />
<h3 style="text-align: left;">Polyomino Area Magic Tori (PAMT) of Order-6</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhPBROAASLEF44LIUKLX07xmkXTFHLj7uga4iQN2R2aBlbCOc15z-MuBn_Ihomt_YpRlYSkuw-ms5x3XXC5y8ObaUzdvvn97PsxftybUvoqJ6OvrL1fZoOnTCkgn4DfsrxR8n_6QPwFiFzBbHjl8wCVa-w0VsFCikXG8flaFPmMA_rlqag1u8LhXyZn/s772/W_MT_Ord-6_sums_111_V1.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="768" data-original-width="772" height="187" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhPBROAASLEF44LIUKLX07xmkXTFHLj7uga4iQN2R2aBlbCOc15z-MuBn_Ihomt_YpRlYSkuw-ms5x3XXC5y8ObaUzdvvn97PsxftybUvoqJ6OvrL1fZoOnTCkgn4DfsrxR8n_6QPwFiFzBbHjl8wCVa-w0VsFCikXG8flaFPmMA_rlqag1u8LhXyZn/s320/W_MT_Ord-6_sums_111_V1.png" width="187" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Partially Pandiagonal Torus type n° T6 of order-6. Magic sums = 111.<br /><i>Please note that this is not a Polyomino Area Magic Torus.</i></td></tr></tbody></table>
<p style="text-align: justify;"><a href="https://budshaw.ca/KnightMove6.html" target="_blank">Harry White</a> has kindly authorised me to use this order-6 magic square viewpoint. With a supplementary <a href="https://en.wikipedia.org/wiki/Broken_diagonal" target="_blank">broken magic diagonal</a> (24, 19, 31, 3, 5, 29), this partially pandiagonal torus displays 4 partially pandiagonal squares and 32 semi-magic squares. In "Extra-Magic Tori and Knight Move Magic Diagonals" it is shown to be an <a href="https://carresmagiques.blogspot.com/2020/04/extra-magic-tori-and-knight-move-magic-diagonals.html" target="_blank">Extra-Magic Partially Pandiagonal Torus of Order-6 with 6 Knight Move Magic Diagonals</a>. This is one of 2627518340149999905600 magic and semi-magic tori of order-6 (total deduced from findings by <a href="https://arxiv.org/abs/1807.02983" target="_blank">Artem Ripatti</a> - see <a href="https://oeis.org/A271104" target="_blank">OEIS A271104</a><a href="https://oeis.org/A271104" target="_blank"> "Number of magic and semi-magic tori of order n composed of the numbers from 1 to n^2"</a>).</p>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHeQtiddzqk2Y0dIZ9AU-MiVveztDMLQYtG3CVhDfD8zoBkwvYsFzNiO09FTeX94hQX0BWTYJyY4pb_-TbXAUnV0425WNgHfIc6k273FZ1nRiQ8s4QQ7o4k7UrlqetMMpZtFid-Cs5AGcvNJlm-HCGbLqr92Rxkh-ABn8stj1XI7s7wlSNhPe5YT2y/s6571/W_PAMT_Ord-6_sums_111_heptominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a partially pandiagonal Polyomino Area Magic Torus of order-6, made with heptominoes by William Walkington" border="0" data-original-height="2525" data-original-width="6571" height="199" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHeQtiddzqk2Y0dIZ9AU-MiVveztDMLQYtG3CVhDfD8zoBkwvYsFzNiO09FTeX94hQX0BWTYJyY4pb_-TbXAUnV0425WNgHfIc6k273FZ1nRiQ8s4QQ7o4k7UrlqetMMpZtFid-Cs5AGcvNJlm-HCGbLqr92Rxkh-ABn8stj1XI7s7wlSNhPe5YT2y/w640-h246/W_PAMT_Ord-6_sums_111_heptominoes.png" title="Partially Pandiagonal Polyomino Area Magic Torus (PAMT) of order-6. Magic sums = 111. Heptominoes, Version 1, Viewpoint 1/36." width="518" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Partially Pandiagonal Polyomino Area Magic Torus (PAMT) of order-6. Magic sums = 111.<br /><a href="https://en.wikipedia.org/wiki/Heptomino" target="_blank">Heptominoes</a>, Version 1, Viewpoint 1/36. <br />Consecutively numbered areas 1 to 36, in an oblong 111 ⋅ 42 = 4662 units.</td></tr></tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhCaKU1fswuuY16LUg3gK2go9GGgezF2kmDToe5LkOS0rNAWmiy9d1gYRh7C8rZPtfat6yLjWvItzK-eFfjMCSHUoBmcc8iMJHl-UnwABOrR72rUMaM-t_V1wDruEsG1YDGSoVcL9VV4nptKcf4g56ViVwXKcovFKMbNsN2qeSw47GNjQODa04v82OB/s4546/W_PAMT_Ord-6_sums_147_dominoes.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of a square Polyomino Area Magic Torus of order-6 with domino tiles, V1 created by William Walkington in 2022" border="0" data-original-height="4546" data-original-width="4546" height="375" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhCaKU1fswuuY16LUg3gK2go9GGgezF2kmDToe5LkOS0rNAWmiy9d1gYRh7C8rZPtfat6yLjWvItzK-eFfjMCSHUoBmcc8iMJHl-UnwABOrR72rUMaM-t_V1wDruEsG1YDGSoVcL9VV4nptKcf4g56ViVwXKcovFKMbNsN2qeSw47GNjQODa04v82OB/w400-h400/W_PAMT_Ord-6_sums_147_dominoes.png" title="Partially Pandiagonal Polyomino Area Magic Torus (PAMT) of order-6. Sums = 147. Dominoes, Version 1, Viewpoint 1/36." width="375" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Partially Pandiagonal Polyomino Area Magic Torus (PAMT) of order-6. Sums = 147.<br /><a href="https://en.wikipedia.org/wiki/Domino_(mathematics)" target="_blank">Dominoes</a>, Version 1, Viewpoint 1/36.<br />Consecutively numbered areas 7 to 42, in a square 42 ⋅ 42 = 1764 units.</td></tr></tbody></table>
<br />
<h3 style="text-align: justify;">Observations</h3>
<p style="text-align: justify;">As they are the first of their kind, these Polyomino Area Magic Tori (PAMT) can most likely be improved: The examples illustrated above are all constructed with their cells aligned horizontally or vertically; and though it is convenient to do so, because it allows their representation as oblongs or squares, this method of constructing PAMT is not obligatory. Representations of PAMT that have irregular rectangular contours may well give better results, with less-elongated cells and simpler cell connections. </p><p style="text-align: justify;">While the use of polyominoes has the immense advantage of allowing the construction of area magic tori with easily quantifiable units, it also introduces the constraint of the tiling of the cells. It has been seen in the examples above that the PAMT can be represented as oblongs or as squares, while other irregular rectangular solutions also exist. A normal magic square of order-3 displays the numbers 1 to 9 and has a total of 45, which is not a perfect square. As the smallest addition to each of the nine numbers 1 to 9, in order to reach a perfect square total is four (45 + 9 ⋅ 4 = 81), this implies that when searching for a <i>square</i> PAMT with consecutive areas of 1 to 9, <i>in theory </i>the smallest polyominoes for this purpose will<i> </i>be pentominoes. <br /></p><p style="text-align: justify;">But to date, in the various shaped examples of PAMT shown above, the smallest cell area used to represent the area 1 is a tetromino, as this gives sufficient flexibility for the connections of a nine-cell PAMT of order-3 with consecutive areas of 1 to 9. <a href="https://www.cs.purdue.edu/homes/gnf/book/Booknews/edoscub7.html" target="_blank">Edo Timmermans</a> has already constructed a <a href="https://twitter.com/alytile/status/1396758907582779397" target="_blank">Polyomino Area Magic Square of order-3</a> using pentominoes for the consecutive areas of 1 to 9, but it seems that such polyominoes cannot be used for the construction of a same-sized and shaped PAMT of order-3. <a href="https://mathworld.wolfram.com/StraightPolyomino.html" target="_blank">Straight polyominoes</a> are always used in the examples given above, as these facilitate long connections, but other polyomino shapes will in some cases be possible.<br /></p><p style="text-align: justify;">We should keep in mind that the PAMT are theoretical, in that, per se, they cannot tile a torus: As a consequence of <a href="https://en.wikipedia.org/wiki/Carl_Friedrich_Gauss" target="_blank">Carl Friedrich Gauss's</a> <i><a href="https://en.wikipedia.org/wiki/Theorema_Egregium" target="_blank">"Theorema Egregium"</a></i>, and because the <a href="http://www.rdrop.com/~half/math/torus/shape.operator.xhtml#GaussianCurvature" target="_blank">Gaussian curvature of the torus</a> is not always zero, there is no local isometry between the torus and a flat surface: We can't flatten a torus without distortion, which therefore makes a perfect map of that torus impossible. Although we can create conformal maps that preserve angles, these do not
necessarily preserve lengths, and are not ideal for our purpose. And while two topological spheres are conformally equivalent, different
topologies of tori can make these conformally distinct and lead to further mapping complications. For those wishing to know more, the paper by <a href="https://en.wikipedia.org/wiki/John_M._Sullivan_(mathematician)" target="_blank">Professor John M. Sullivan</a>, entitled <a href="https://static1.bridgesmathart.org/2011/cdrom/proceedings/134/paper_134.pdf" target="_blank">"Conformal Tiling on a Torus"</a>, makes excellent reading.</p><p style="text-align: justify;">Notwithstanding their theoreticality, the PAMT nevertheless offer an interesting field of research that transcends the complications of tiling doubly-curved torus surfaces, while suggesting interesting patterns for planar tiling: For
those who are not convinced by 9-colour tiling, 2-colour pandiagonal tiling
can also be a good choice for geeky living spaces:</p>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiu6OzvZJ0j6PiTHJlVhPitR6GqBDWMK13FUII6-K7BoEGKnD64XeimtbgnuLF-QLUx2S8vF4BqBlSN7BbeFwq7rx-f70X3Xe0W3Whfl5lkHGiRJgKZyzaC1X4F2I8fIhSHoxAFvEXB7ObARuLQIv8hPd-Tw4VwfcsczBZv0AGyd1YKfoJjYgZs8nvA/s4312/W_Irreg_PAMT_Ord-3_tiling.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of irregular rectangular Polyomino Area Magic Torus tiling of order-3 with monominoes, by William Walkington in 2022" border="0" data-original-height="4312" data-original-width="3961" height="435" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiu6OzvZJ0j6PiTHJlVhPitR6GqBDWMK13FUII6-K7BoEGKnD64XeimtbgnuLF-QLUx2S8vF4BqBlSN7BbeFwq7rx-f70X3Xe0W3Whfl5lkHGiRJgKZyzaC1X4F2I8fIhSHoxAFvEXB7ObARuLQIv8hPd-Tw4VwfcsczBZv0AGyd1YKfoJjYgZs8nvA/w589-h640/W_Irreg_PAMT_Ord-3_tiling.png" title="Tiling with irregular rectangular shaped PAMT of order-3. Monominoes. S=24." width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Tiling with irregular rectangular shaped PAMT of order-3. <a href="https://en.wikipedia.org/wiki/Polyomino" target="_blank">Monominoes</a>. S=24.</td></tr></tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSM0DwwUdMsHM3_NWlIl0RSN3JjkhkwRlmobtjeCYCNDzGXut4jp7Zd-jM57aB5oyKgw8JaqidATXyawOgnCrpr65R7clkBvkRdmIJiSCjSkpp3BrJzv7hc-dFmDGNHUN7BznXocl766P9gyppINsSdXZiy9LNFP5zBVfKDTEUiihrIob2h2ntpQ6N/s4344/W_Irreg_PAMT_S15_Ord-3_tiling.png" style="margin-left: auto; margin-right: auto;"><img alt="Diagram of irregular rectangular Polyomino Area Magic Torus tiling of order-3 with tetromino tiles, by William Walkington in 2022" border="0" data-original-height="3265" data-original-width="4344" height="390" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSM0DwwUdMsHM3_NWlIl0RSN3JjkhkwRlmobtjeCYCNDzGXut4jp7Zd-jM57aB5oyKgw8JaqidATXyawOgnCrpr65R7clkBvkRdmIJiSCjSkpp3BrJzv7hc-dFmDGNHUN7BznXocl766P9gyppINsSdXZiy9LNFP5zBVfKDTEUiihrIob2h2ntpQ6N/w640-h482/W_Irreg_PAMT_S15_Ord-3_tiling.png" title="Tiling with irregular rectangular shaped PAMT of order-3. Tetrominoes. S=15." width="518" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Tiling with irregular rectangular shaped PAMT of order-3. <a href="https://en.wikipedia.org/wiki/Tetromino" target="_blank">Tetrominoes</a>. S=15.</td></tr></tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcqYH5ALLC6VDbUJB3dmiad9dGy1hEoYmpBbrEJ_-n_sZvEsgDRm6Yd2cxgeYIzCbwp1zxFL4Um0z0-y4N7wKvITKjry2ml9Zk-NfrBN6GeMdtZObIoeYAiwiSc-3b5bbTQhmA0lXg_K2CEl1Ht2SBi7YqXqUj3Hh7VeNxptQ3P0_6GBOHQ3TEJxul/s4287/W_Irreg_PAMT_S18_Ord-3_tiling.png" style="margin-left: auto; margin-right: auto;"><img alt="Diagram of irregular rectangular Polyomino Area Magic Torus tiling of order-3 with tromino tiles, by William Walkington in 2022" border="0" data-original-height="4287" data-original-width="2324" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcqYH5ALLC6VDbUJB3dmiad9dGy1hEoYmpBbrEJ_-n_sZvEsgDRm6Yd2cxgeYIzCbwp1zxFL4Um0z0-y4N7wKvITKjry2ml9Zk-NfrBN6GeMdtZObIoeYAiwiSc-3b5bbTQhmA0lXg_K2CEl1Ht2SBi7YqXqUj3Hh7VeNxptQ3P0_6GBOHQ3TEJxul/w346-h640/W_Irreg_PAMT_S18_Ord-3_tiling.png" title="Tiling with irregular rectangular shaped PAMT of order-3. Trominoes. S=18." width="346" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Tiling with irregular rectangular shaped PAMT of order-3. <a href="https://en.wikipedia.org/wiki/Tromino" target="_blank">Trominoes</a>. S=18.</td></tr></tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgV5Zxt7NJom23CAni9TBkRMsNDIHySqAku01ldmnEAdAFZcAXaW9EzimzpLJkkq2ynpS2Wf-ceWvxFo-rmBO544WRgo8NBxixOQXfOk_Jlqazvqk-QZ2TZFOfwc4SNv9iVMy6vr1gIdJgcWiWqyrQFsYOq5lVJHDZL5AvNWg_3o1nT-egV9j4ZYHVz/s4034/W_Oblong_PAMT_Ord-3_tiling.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of oblong Polyomino Area Magic Torus tiling of order-3 with tromino tiles, created by William Walkington in 2022" border="0" data-original-height="4034" data-original-width="3591" height="478" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgV5Zxt7NJom23CAni9TBkRMsNDIHySqAku01ldmnEAdAFZcAXaW9EzimzpLJkkq2ynpS2Wf-ceWvxFo-rmBO544WRgo8NBxixOQXfOk_Jlqazvqk-QZ2TZFOfwc4SNv9iVMy6vr1gIdJgcWiWqyrQFsYOq5lVJHDZL5AvNWg_3o1nT-egV9j4ZYHVz/w570-h640/W_Oblong_PAMT_Ord-3_tiling.png" title="Tiling with oblong PAMT of order-3. Trominoes. S=24." width="426" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Tiling with oblong PAMT of order-3. <a href="https://en.wikipedia.org/wiki/Tromino" target="_blank">Trominoes</a>. S=24.</td></tr></tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-Qs9KdMyDe8txrFOzs4aeBl_K_xc8wsSgvEbSftDdLoz--EjxTc17YN6mBCvMJdraCwTwyJ-oF1TBci9j1zKTDMu3Qk0TUZKeBIkCjeu07bOfbt2bS3hUnFNJF_GP2jzl-KZ_9imLRLQK_PvftRH1pJLLyr70_y1tquDIGXBROAru2zvRxRdRyOLa/s3586/W_Pandiagonal_PAMT_Ord-4_tiling.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of oblong Polyomino Area Magic Torus tiling of order-4 with pentomino tiles, by William Walkington in 2022" border="0" data-original-height="3171" data-original-width="3586" height="458" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-Qs9KdMyDe8txrFOzs4aeBl_K_xc8wsSgvEbSftDdLoz--EjxTc17YN6mBCvMJdraCwTwyJ-oF1TBci9j1zKTDMu3Qk0TUZKeBIkCjeu07bOfbt2bS3hUnFNJF_GP2jzl-KZ_9imLRLQK_PvftRH1pJLLyr70_y1tquDIGXBROAru2zvRxRdRyOLa/w640-h566/W_Pandiagonal_PAMT_Ord-4_tiling.png" title="Tiling with oblong pandiagonal PAMT of order-4. Pentominoes. S=34." width="518" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Tiling with oblong pandiagonal PAMT of order-4. <a href="https://en.wikipedia.org/wiki/Pentomino" target="_blank">Pentominoes</a>. S=34.</td></tr></tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXVTgEwZMl9sZbv0X3u4TatQFlWrwmfLckcsFLM063qNMdGwhl0Oak_ZjVbKVnd5BFx9XuTElgvelNO-rmzyRrMjqV4yDIQl6oN_wyRmgrMIep0LJL8qBpXmlPOf_IHYmPjLD8yoFrFRewKtSSFxMXEI1zq54lQgrRQRhs6dqQXpSDRlx_QIbT7X9w/s4190/W_Pandiagonal_PAMT_Ord-5_tiling_S65.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of oblong Polyomino Area Magic Torus tiling of order-5 with hexomino tiles, by William Walkington in 2022" border="0" data-original-height="2904" data-original-width="4190" height="359" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXVTgEwZMl9sZbv0X3u4TatQFlWrwmfLckcsFLM063qNMdGwhl0Oak_ZjVbKVnd5BFx9XuTElgvelNO-rmzyRrMjqV4yDIQl6oN_wyRmgrMIep0LJL8qBpXmlPOf_IHYmPjLD8yoFrFRewKtSSFxMXEI1zq54lQgrRQRhs6dqQXpSDRlx_QIbT7X9w/w640-h444/W_Pandiagonal_PAMT_Ord-5_tiling_S65.png" title="Tiling with oblong pandiagonal PAMT of order-5. Hexominoes. S=65." width="518" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Tiling with oblong pandiagonal PAMT of order-5. <a href="https://en.wikipedia.org/wiki/Hexomino" target="_blank">Hexominoes</a>. S=65.</td></tr></tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7t8ofyUv49vVnlUy-NEs6QiS1eek2CvwMu9b6JptJYlfxdu7zJbm3RAT2qkZiYGeW8zRqmh2EssPQOp0yLwuFqq00I9rhbQiWCJ1GAszw920vhzj-V2Wr9ijzKTk8CivqetXAIGIq-DCQHrXpi2nf3zmMohsOoxha6MKTSz-soVlGxvsMVQWU8P5D/s4427/W_Pandiagonal_PAMT_Ord-5_tiling.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of square Polyomino Area Magic Torus tiling of order-5 with monomino tiles, created by William Walkington in 2022" border="0" data-original-height="4421" data-original-width="4427" height="518" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7t8ofyUv49vVnlUy-NEs6QiS1eek2CvwMu9b6JptJYlfxdu7zJbm3RAT2qkZiYGeW8zRqmh2EssPQOp0yLwuFqq00I9rhbQiWCJ1GAszw920vhzj-V2Wr9ijzKTk8CivqetXAIGIq-DCQHrXpi2nf3zmMohsOoxha6MKTSz-soVlGxvsMVQWU8P5D/w640-h640/W_Pandiagonal_PAMT_Ord-5_tiling.png" title="Tiling with square pandiagonal PAMT of order-5. Monominoes. S=125." width="518" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Tiling with square pandiagonal PAMT of order-5. <a href="https://en.wikipedia.org/wiki/Polyomino" target="_blank">Monominoes</a>. S=125.</td></tr></tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgbivnh6doSlc3hNSUtXLDcmlpEcIgjUEjMkZCSTfUoIzUstjPihd1N7sVpG_c-ofWBnwtDoZXMjpE2j6DrtZqan6YucFf12hEM2cWFlFODWmiv_AnlmRQey7M_qq_dvPpnWSGaFQQ9DgqEajPBsWvQH7NGDvkkgQiUs76MDA8-ALFyyh5-Uyd1Qm98/s2001/W_PAMT_Ord-6_sums_111_tiling.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of oblong Polyomino Area Magic Torus tiling of order-6 with heptomino tiles, by William Walkington in 2022" border="0" data-original-height="1139" data-original-width="2001" height="295" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgbivnh6doSlc3hNSUtXLDcmlpEcIgjUEjMkZCSTfUoIzUstjPihd1N7sVpG_c-ofWBnwtDoZXMjpE2j6DrtZqan6YucFf12hEM2cWFlFODWmiv_AnlmRQey7M_qq_dvPpnWSGaFQQ9DgqEajPBsWvQH7NGDvkkgQiUs76MDA8-ALFyyh5-Uyd1Qm98/w640-h364/W_PAMT_Ord-6_sums_111_tiling.png" title="Tiling with oblong partially pandiagonal PAMT of order-6. Heptominoes. S=111." width="518" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Tiling with oblong partially pandiagonal PAMT of order-6. <a href="https://en.wikipedia.org/wiki/Heptomino" target="_blank">Heptominoes</a>. S=111.</td></tr></tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiL3upnaT6peP3E8CZMpj67jgB31Gw4PeFg1QbQhuoRRd5cA0QB8W4H5x_vxF75tg_kOBSJ68v_luih1ocWylZ-O5F1GsMz97y1a2u1sfrY9K2kTRFTOe3ZIYZnp001LAJt7XvvjleUV7A1ypR0qCzPHgvN_woMY26hwST2G3-sLi8QoMNPEQETQvR1/s1907/W_PAMT_Ord-6_tiling.png" style="margin-left: auto; margin-right: auto;"><img alt="Colour diagram of square Polyomino Area Magic Torus tiling of order-6 with domino tiles, by William Walkington in 2022" border="0" data-original-height="1907" data-original-width="1903" height="518" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiL3upnaT6peP3E8CZMpj67jgB31Gw4PeFg1QbQhuoRRd5cA0QB8W4H5x_vxF75tg_kOBSJ68v_luih1ocWylZ-O5F1GsMz97y1a2u1sfrY9K2kTRFTOe3ZIYZnp001LAJt7XvvjleUV7A1ypR0qCzPHgvN_woMY26hwST2G3-sLi8QoMNPEQETQvR1/w638-h640/W_PAMT_Ord-6_tiling.png" title="Tiling with square partially pandiagonal PAMT of order-6. Dominoes. S=147." width="518" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Tiling with square partially pandiagonal PAMT of order-6. <a href="https://en.wikipedia.org/wiki/Domino_(mathematics)" target="_blank">Dominoes</a>. S=147.</td></tr></tbody></table>
<br />
<p style="text-align: justify;">There are still plenty of other interesting PAMT that remain to be found, and I hope you will authorise me to publish or relay your future discoveries and suggestions!</p>
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com4tag:blogger.com,1999:blog-8742944687733483108.post-85084501515610775782021-09-20T17:45:00.047+02:002023-06-19T22:53:58.923+02:00How Dürer's "Melencolia I" is a painful but liberating metamorphosis!<img alt="" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpFf1gdknMBBfk2-Puk4Fzn3hLMNcXsHerGvsOVsdg0nIdmbOnEpv3ZfJGK3Mgnlk0pktlhFNjL9tgMcj94J4YCRS3KOpPuk7Ir79VkpB73mi8HIf4_w2Qu2rVRJ_gGJrJPZsBbwrRKgU/w400-h211/bat-like+beast.jpg" style="display: none;" />
<div style="text-align: justify;">
The title of this post may at first seem rather strange, especially when we
know that the main subjects of these pages are "Magic Squares, Spheres and
Tori." However, the famous
<a href="https://en.wikipedia.org/wiki/Melencolia_I" target="_blank">"Melencolia I"</a>
engraving by
<a href="https://en.wikipedia.org/wiki/Albrecht_D%C3%BCrer" target="_blank">Albrecht Dürer</a>
does depict, amongst other symbols, a magic square of order-4 (already
examined in
<a href=" https://carresmagiques.blogspot.com/2014/12/melancholy-in-magic-squares-tribute-to.html" target="_blank">"A Magic Square Tribute to Dürer, 500+ Years After Melencolia I,"</a>
and
<a href="https://carresmagiques.blogspot.com/2020/04/pan-zigzag-magic-tori-that-magnify-the-Durer-magic-square.html" target="_blank">"Pan-Zigzag Magic Tori Magnify the "Dürer" Magic Square"</a>).
</div>
<div style="text-align: justify;"><br /></div>
<div style="text-align: justify;">
In the section reserved for correspondence at the end of the post
<a href="https://carresmagiques.blogspot.com/2014/12/melancholy-in-magic-squares-tribute-to.html" target="_blank">"A Magic Square Tribute to Dürer, 500+ Years After Melencolia I,"</a>
I have recently received some interesting comments from
<a href="https://sketchportraitstudio.wordpress.com/category/gallery-blog/" target="_blank">Rob Sellars</a>. Rob looks at Dürer's engraving from a Judaic point of view and describes
the bat-like animal (at the top left) as a flying chimera which has a
combination of the
<a href="https://judaism.stackexchange.com/questions/57276/what-is-a-tinshemet" target="_blank">Tinshemet features</a>
of the "flying waterfowl and the earth mole." Rob's description has made me
look harder at this beast, and in doing so, I have noticed some aspects that
explain the very essence of "Melencolia I."
</div>
<div style="text-align: justify;"> </div>
<div style="text-align: justify;">
<h2>The Historical Context</h2>
<div><br /></div>
The year 1514 CE came during a turbulent historical period, just three years
before the
<a href="https://en.wikipedia.org/wiki/Reformation" target="_blank">Protestant Reformation</a>, and the seemingly endless wars of religion which would follow. When
Albrecht Dürer created "Melencolia I," he was expressing the philosophical,
scientific, and humanist ideas of fifteenth-century Italy, and thus
contributing to the beginning of a new phase of the
<a href="https://en.wikipedia.org/wiki/Northern_Renaissance" target="_blank">Renaissance</a>. Dürer was one of the first artists of Northern Europe to understand the
importance of the Greek classics, and particularly the ideas of Plato and
Socrates. The Renaissance idea was revolutionary, as it suggested that
everyone was created <i>"in imago Dei,"</i> in the image of God, and was
capable of developing himself, or herself, to participate in the creation of
the universe. This idea was now being gradually transmitted to all classes of
society, thanks to the invention of the printing press; but it required a
metaphorical language which could be deciphered by all, especially in a
largely illiterate population. Although most of Dürer’s prints were intended
for this wide public, his three master engravings (<a href="https://en.wikipedia.org/wiki/Meisterstiche_(D%C3%BCrer)" target="_blank"><i>“Meisterstiche”</i></a>), which include "Melencolia I," were aimed instead at a more discerning
circle of fellow humanists and artists. The messages were more intellectual,
using subtle symbols that would not be evident for common men, but could be
decrypted by those initiated in the art.<br /><br />
</div>
<div style="text-align: left;">
<h2 style="text-align: left;">
The Metamorphosis of the Flying Creature<br /><br />
</h2>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;">
<tbody>
<tr>
<td style="text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpFf1gdknMBBfk2-Puk4Fzn3hLMNcXsHerGvsOVsdg0nIdmbOnEpv3ZfJGK3Mgnlk0pktlhFNjL9tgMcj94J4YCRS3KOpPuk7Ir79VkpB73mi8HIf4_w2Qu2rVRJ_gGJrJPZsBbwrRKgU/s2048/bat-like+beast.jpg" style="margin-left: auto; margin-right: auto;"><img alt="In the cartouche of Dürer's "Melencolia I", what at first looks like a flying bat is in fact a self-disembowelled flying rat!" border="0" data-original-height="1079" data-original-width="2048" height="272" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpFf1gdknMBBfk2-Puk4Fzn3hLMNcXsHerGvsOVsdg0nIdmbOnEpv3ZfJGK3Mgnlk0pktlhFNjL9tgMcj94J4YCRS3KOpPuk7Ir79VkpB73mi8HIf4_w2Qu2rVRJ_gGJrJPZsBbwrRKgU/w400-h211/bat-like+beast.jpg" title="The cartouche of Dürer's "Melencolia I"" width="518" /></a>
</td>
</tr>
<tr>
<td class="tr-caption" style="text-align: center;">
<span style="font-size: xx-small;">Detail of the bat-like beast at the top left-hand side of
"Melencolia I" </span><span style="font-size: xx-small;">which was engraved by </span><span style="font-size: xx-small;"><span style="font-size: xx-small;">Albrecht Dürer i</span>n 1514
</span>
</td>
</tr>
</tbody>
</table>
<br />
</div>
<p style="text-align: justify;">
At first sight, the cartouche at the top left-hand side of Dürer's "Melencolia
I" seems to be a flying bat, bearing the title of the engraving on its open
wings. The length and thickness of the tail both look oversized, but we can
suppose that Dürer was using his artistic licence to amplify the visual impact
of the swooping beast. Nearly all species of bats have tails, even if most (if
not all) of these, are shorter and thinner than the one that Dürer has
depicted. <br />
<br />But looking again with more attention, we can see that, quite weirdly,
the body of the animal is placed above its wings, which is impossible unless
the bat is flying upside-down! Closer examination suggests that this is not
the case, as the mouth and eyes of the beast are clearly those of an animal
with an upright head. All the same, we might well ask where the hind feet are,
and how the creature can possibly make a safe landing without these!<br /><br />
Looking once again more closely, we can see another, even more troubling
detail, in that the “wings,” which carry the title of the engraving, are in
fact two large strips of ragged skin, ripped outwards from the belly, as if
the animal has disembowelled itself!<br />
<br />Judging from the thickness of its tail and the form of its head, the
airborne creature was initially a rat before it began its painful
metamorphosis. It has since carried out an auto-mutilation, and is now showing
its inner melancholy to the outer world, but at the same time flying free with
its hard-earned wings!
</p>
<p style="text-align: justify;">
Symbolically, the cartouche is telling us that ""Melencolia I" is a painful
metamorphosis which precedes a liberating <i>"Renaissance!"</i>"<br />
</p>
<h2 style="text-align: justify;">How Melancholy leads to Renaissance<br /></h2>
<p style="text-align: justify;">
During 1514 CE the artist's mother,
<a href="https://fr.wikipedia.org/wiki/Barbara_D%C3%BCrer" target="_blank">Barbara Dürer</a>
(née Holper), passed away, or “died hard” as he described it, and we can
therefore suppose that Dürer’s grief would have been a strong catalyst of the
very melancholic atmosphere depicted in his “Melencolia I.” The melancholy,
referred to in the title of the engraving, is illustrated by an extraordinary
collection of symbols that fill the scene. Some of these are tools associated
with craft and carpentry. Others are objects and instruments that refer to
alchemy, geometry or mathematics. In addition to the bat-like beast, the sky
also contains what might be a
<a href="https://en.wikipedia.org/wiki/Moonbow" target="_blank">moonbow</a>
and a <a href="https://en.wikipedia.org/wiki/Comet" target="_blank">comet</a>.
Further symbols include a
<a href="https://en.wikipedia.org/wiki/Putto" target="_blank">putto</a> seated
on a millstone, and a robust winged person, also seated, which could well be
an allegorical self-portrait. These, and many other symbols, are the object of
multiple interpretations by various authors. Some scholars consider the
engraving to be an
<a href="https://en.wikipedia.org/wiki/Allegory" target="_blank">allegory</a>,
which can be interpreted through the correct comprehension of the symbols,
while others think that the ambiguity is intentional, and designed to resist
complete interpretation. I tend to agree with the latter point of view, and
think that the confusion symbolises the unfinished studies and works of the
main melancholic figure; an apprentice
<a href="https://en.wikipedia.org/wiki/Angel" target="_blank">angel</a>, who
believes that despite his worldly efforts, he lacks inspiration, and is not
making sufficient progress.<br />
</p>
<p style="text-align: justify;">
Notwithstanding the melancholy that reigns, there is still hope: The 4 x 4
magic square, for example, has the same dimension as
<a href="https://en.wikipedia.org/wiki/Magic_square#Europe_after_15th_century" target="_blank">Agrippa's Jupiter square</a>, a talisman that supposedly counters melancholy. The intent expression of
the main winged person suggests a determination to overcome his doubts, and
transcend the obstacles that continue to block his progression. Positive
symbols of a resurrection or <i>"Renaissance"</i> are also plainly visible,
not only in the hard-earned wings of the flying creature, but also in the
growing wings that Dürer gives himself in his portrayal as the apprentice
angel. <br />
</p>
<div style="text-align: left;"><br /></div>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;">
<tbody>
<tr>
<td style="text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhX0KWFhW_LD7E2oP2QO3euG1vc_MmUqjAk2x-VyBBKfQwlOWHfhTGpDCfCrJnrX3hR2Zz-vLRBhqpTCh6dnIU7XhLAUM2zZmZYwdro2OKl5BaCaPT2GHbI60myGTExABOFpYAZp0xSvkU/s2048/Melencolia+I.jpg" style="margin-left: auto; margin-right: auto;"><img alt=""Melencolia I," engraved by Albrecht Dürer in 1514, is an illustration of the artist's melancholy, and is filled with symbols." border="0" data-original-height="2048" data-original-width="1606" height="660" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhX0KWFhW_LD7E2oP2QO3euG1vc_MmUqjAk2x-VyBBKfQwlOWHfhTGpDCfCrJnrX3hR2Zz-vLRBhqpTCh6dnIU7XhLAUM2zZmZYwdro2OKl5BaCaPT2GHbI60myGTExABOFpYAZp0xSvkU/w502-h640/Melencolia+I.jpg" title=""Melencolia I" engraved by Albrecht Dürer in 1514" width="518" /></a>
</td>
</tr>
<tr>
<td class="tr-caption" style="text-align: center;">
<span style="font-size: xx-small;">"Melencolia I" engraved by Albrecht Dürer in 1514<br /></span>
</td>
<td class="tr-caption" style="text-align: center;"><br /></td>
</tr>
</tbody>
</table>
<p style="text-align: justify;">
On page 171 of his book entitled <a href="https://monoskop.org/images/d/d0/Panofsky_Erwin_The_Life_and_Art_of_Albrecht_Duerer_1955.pdf#page_100" target="_blank">"The Life and Art of Albrecht Dürer,"</a>
<a href="https://en.wikipedia.org/wiki/Erwin_Panofsky" target="_blank">Erwin Panofsky</a>
considers that "Melencolia I" is the spiritual self-portrait of the artist.
There is indeed much resemblance between the features of the apprentice angel,
and those of the engraver in previous self-portraits.<br />
</p>
<p style="text-align: justify;">
Dürer had already adopted a striking religious pose in his last
<i>declared</i> self-portrait of 1500 CE, giving himself
<a href="https://en.wikipedia.org/wiki/Self-Portrait_(D%C3%BCrer,_Munich)" target="_blank">a strong resemblance to Christ</a>
by respecting the iconic pictorial conventions of the time. In other presumed
self-portraits, (but not declared as such), Dürer had also presented himself
in a Christic manner; in his c.1493
<a href="https://www.albrechtdurer.org/man-of-sorrows/" target="_blank">"Christ as a Man of Sorrows;"</a>
and in his 1503
<a href="https://www.bmimages.com/preview.asp?image=00241965001&imagex=44&searchnum=0001" target="_blank">"Head of the Dead Christ."</a>
What is more, Dürer inserted his self-portraits in altarpieces; in 1506 for
the San Bartolomeo church in Venice (<a href="https://art-in-space.blogspot.com/2015/09/albrecht-durer-feast-of-rose-garlands.html" target="_blank">"Feast of Rose Garlands")</a>; in 1509 for the Dominican Church in Frankfurt (<a href="https://en.wikipedia.org/wiki/Heller_Altarpiece" target="_blank">"Heller Altarpiece"</a>); and in 1511 for a Chapel in Nuremberg's "House of Twelve Brothers" (<a href="https://en.wikipedia.org/wiki/Adoration_of_the_Trinity" target="_blank">"Landauer Altarpiece"</a>
or "The Adoration of the Trinity"). Thus Dürer was already a master of
religious
<a href="https://mymodernmet.com/famous-self-portraits/" target="_blank">self-portraiture</a>
when he engraved "Melencolia I" in 1514, and he might well have continued in
the same manner. But this time, probably because the theological,
philosophical and humanistic ideas of the Renaissance were not only
spiritually, but also intellectually inspiring, he went even further, and gave
himself wings!
</p>
<h2 style="text-align: justify;">Acknowledgement</h2>
<p style="text-align: justify;">
Passages of "The Historical Context" are inspired by the writings of Bonnie
James, in her excellent article
<a href="https://archive.schillerinstitute.com/fidelio_archive/2005/fidv14n03-2005Fa/fidv14n03-2005Fa.pdf#page=80&zoom=auto,-20,3" target="_blank">"Albrecht Dürer: The Search for the Beautiful In a Time of Trials"</a>
(Fidelio Volume 14, Number 3, Fall 2005), a publication of the
<a href="https://archive.schillerinstitute.com/about/about.html" target="_blank">Schiller Institute</a>.
</p>
<h2 style="text-align: justify;">Latest Development<br /></h2>
<p style="text-align: justify;">
After reading this article,
<a href="https://www.region.com.ar/amela/franklinsquares/" target="_blank">Miguel Angel Amela</a>
(who like me, is not only interested in magic squares, but also in
"Melencolia I") sent me his thanks by email, and enclosed <i>"a paper of 2020
about a painful love triangle..."</i> His paper is entitled
<a href="https://drive.google.com/file/d/1D9psHThm43YJTsOXuF6oRBLJ-I65aF46/view?usp=sharing" target="_blank">"A Hidden Love Story"</a>
and interprets the "portrait of a young woman with her hair done up," which was first
painted
by
Albrecht Dürer
in 1497, and then reproduced in an
engraving
by
<a href="https://en.wikipedia.org/wiki/Wenceslaus_Hollar" target="_blank">Wenceslaus Hollar</a>, almost 150 years later in 1646. Miguel's story is captivating, and I wish to
thank him for kindly authorising me to publish it <a href="https://drive.google.com/file/d/1D9psHThm43YJTsOXuF6oRBLJ-I65aF46/view" target="_blank">here</a>.<br />
</p>
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-42404739247280688492020-08-02T19:35:00.048+02:002023-06-19T22:54:51.311+02:00A Bimagic Queen's Tour<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgG0ODce2n-690kbOM_fRs8VMo5s8Nv7O0fC0aeiHZqzYNRsdqFnRcOpqtofRH5zNc_kg2lNwgeQ-ullS6pPhhaKBOX4RwKewu-Qo8dpo2JIcTANgbCrptS5IaRJNG8mFsdFlP2akqm4I/s1600/Bimagic_Queen_s_Tour_200723_WW.gif" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="836" data-original-width="1600" height="208" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgG0ODce2n-690kbOM_fRs8VMo5s8Nv7O0fC0aeiHZqzYNRsdqFnRcOpqtofRH5zNc_kg2lNwgeQ-ullS6pPhhaKBOX4RwKewu-Qo8dpo2JIcTANgbCrptS5IaRJNG8mFsdFlP2akqm4I/w400-h208/Bimagic_Queen_s_Tour_200723_WW.gif" style="display: none;" width="400" /></a></td></tr></tbody></table>
<div style="text-align: justify;">
On the 6th July 2020, enclosing notes written by <a href="https://en.wikipedia.org/wiki/Joachim_Br%C3%BCgge" target="_blank">Joachim Brügge</a>, <a href="https://www.semanticscholar.org/paper/Magic-Knight's-Tours-in-Higher-Dimensions-Kumar/75e8a083e85e21855735c1964cf6992c89f8c107" target="_blank">Awani Kumar</a> sent an e-mail to our circle of magic square enthusiasts, asking whether a bimagic queen's tour might exist on an 8 x 8 or larger board, and invited us to "settle the question." I was intrigued by this interesting challenge, and after a first analysis of Joachim Brügge's approach, and exchanging e-mails with him, I decided to search for a solution.</div>
<div style="text-align: justify;">
<br /></div>
<h2 style="text-align: justify;">
Some Important Definitions</h2>
<br />
<div style="text-align: justify;">
A standard chess board is an 8 x 8 square grid upon which the queen can move any number of squares, either orthogonally, or along ± 1 / ± 1 diagonals. A queen's tour is a sequence of queen's moves in which she visits each of the 64 squares once. If the queen ends her tour on a square which is at a single queen's move from the starting square, the tour is closed; otherwise the queen's tour is open. Here it is useful to clarify the definition of a <i>bimagic queen's tour</i>, which is <i>different to that of a bimagic square</i>: In chess literature, as confirmed by <a href="http://www.mayhematics.com/t/mg.htm#(1)" target="_blank">George Jelliss</a>, the term <i>magic</i> is commonly used for all tours in which the successively numbered positions of the chess piece in each rank and file add up to the same orthogonal total (the magic constant S1), and should the entries on the two long diagonals also add up to the same magic constant, the tour is deemed to be diagonally magic. (In fact, it is now known, thanks to the work of <a href="https://www.jstor.org/stable/3620620?seq=1" target="_blank">G. Stertenbrink, J-C. Meyrignac and H. Mackay</a>, who have completed the list of all of the 140 <i>magic knight tours</i> on an 8 x 8 board, that none of these have two long magic diagonals). Extending the above definition of a magic tour to that of a <i>bimagic</i> queen's tour, not only the successively numbered positions of the queen in each rank and file should add up to a same orthogonal total <i>(the magic constant S1)</i>, but also the <i>squared entries</i> of each rank and file should add up to an additional total which is <i>the bimagic constant S2</i>.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
For a N x N board, when N = 8, the magic constant S1 = 260.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
For a N x N board, when N = 8, <i>the bimagic constant S2 = 11180</i>.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
More information about how the magic and bimagic constants are calculated can be found in the website of <a href="http://multimagie.com/English/Formula.htm" target="_blank">Christian Boyer</a>.</div>
<div style="text-align: justify;">
<br /></div>
<h2 style="text-align: justify;">
The First Hypotheses</h2>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Before beginning the search for a solution to the bimagic queen's tour question, the following hypotheses were considered:</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Firstly, it seemed logical to privilege diagonal queen moves that would be less likely to perturb the orthogonal bimagic series of the ranks and files.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Secondly, it seemed pertinent to make selections from the 240 immutable bimagic series of order-8; series named this way by <a href="http://www.trump.de/magic-squares/bimagic-8/distribution/immutable-series.pdf" target="_blank">Dwane Campbell</a>, who identified and listed these some years ago. 192 of these series have the advantage of having a regular distribution, with each of their eight numbers coming from different eighths of the sequence 1 to 64.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Thirdly, it seemed probable that by using symmetric arrays of bimagic series, this would be beneficial for overall balance, and increase the chances of success.</div>
<div style="text-align: justify;">
<br /></div>
<h2 style="text-align: justify;">
The First Trials and Observations</h2>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Although I was at first unable to find a complete bimagic queen's tour, testing the above hypotheses gradually produced encouraging results. On the 18th July I was able to write an e-mail to Joachim Brügge announcing that I had found several broken bimagic queen's tours, with 4, 3, and even 2 separate sequences.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
In all of these broken tours, because of the characteristics of the bimagic series that were tested, the sequence breaks occurred precisely at certain junctions between the different quarters of N², and it was of utmost importance to find a regular sequence that could negotiate these obstacles with valid diagonal queen's moves.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Also during these early trials I noticed that when certain diagonal moves "exited" the board they "re-entered" it in cells that were no longer directly accessible to the queen. The following diagram shows how this occurs:</div>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg76I3J4LdNWUQ0_DxmdIVRYKCcGd9UemshoVS7rzfQAiQuiN3THUZT4e2cB6nyC3TvVl0kGtVGpWzAwBqwN1CtGju8sXKGVObikUsP5Pmh_bBdXjuW5dJ52a5nznGEUNZmYuLfJqEcPuQ/s1600/Bimagic_Queen_s_Tour_2_2_moves_200723_WW.gif" style="margin-left: auto; margin-right: auto;"><img alt="How some diagonal moves become inaccessible to the queen after "leaving" and "re-entering" the chess board" border="0" data-original-height="1600" data-original-width="1487" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg76I3J4LdNWUQ0_DxmdIVRYKCcGd9UemshoVS7rzfQAiQuiN3THUZT4e2cB6nyC3TvVl0kGtVGpWzAwBqwN1CtGju8sXKGVObikUsP5Pmh_bBdXjuW5dJ52a5nznGEUNZmYuLfJqEcPuQ/s400/Bimagic_Queen_s_Tour_2_2_moves_200723_WW.gif" title="" width="371" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">How certain diagonal moves break the queen's tour</td></tr>
</tbody></table>
<br />
<div style="text-align: justify;">
In order to improve the chances of success of a queen's tour, which was necessarily limited to the board, I realised it would be best to use ± N/2, ± N/2, i.e. ± 4, ± 4 diagonal queen's moves as illustrated below. The advantage of such moves was that when they "left" the board <i>they always "re-entered" it in cells that the queen could once again access</i>, even if along an alternative diagonal. </div>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzOgLgEwE_eyULAJikqegb3MJmTY14sNKak7bP0xyFFcsFfWQG-Ky_QTLA6ImdWWR1VQROJnTA5XcJLUTw_IqPr2bUCvycc3xMiQO_oLKjKtiT0FKBnGn4J3sy6D6RNb2V1sKDswsqyTc/s1600/Bimagic_Queen_s_Tour_4_4_moves_200723_WW.gif" style="margin-left: auto; margin-right: auto;"><img alt="When ± N/2, ± N/2 diagonal moves "leave" the chess board, they always "re-enter" it along a diagonal accessible to the queen.-" border="0" data-original-height="1594" data-original-width="1600" height="397" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzOgLgEwE_eyULAJikqegb3MJmTY14sNKak7bP0xyFFcsFfWQG-Ky_QTLA6ImdWWR1VQROJnTA5XcJLUTw_IqPr2bUCvycc3xMiQO_oLKjKtiT0FKBnGn4J3sy6D6RNb2V1sKDswsqyTc/s400/Bimagic_Queen_s_Tour_4_4_moves_200723_WW.gif" title="" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">± N/2, ± N/2 diagonal moves never break the queen's tour</td></tr>
</tbody></table>
<br />
<div style="text-align: justify;">
In order to optimise the ``convergence" effect of these ± N/2, ± N/2 i.e. ± 4, ± 4 diagonals, they should be used once every two moves.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Despite the inconvenience of their spreading beyond the edges of the board, a large use of ± 2, ± 2 diagonal moves often produced complete, though irregular bimagic queen's tours, such as the one below, observed on the limitless surface of a <a href="https://carresmagiques.blogspot.com/2012/03/from-magic-square-to-magic-torus.html" target="_blank">semi-bimagic torus</a>:</div>
<div class="separator" style="clear: both; text-align: justify;">
</div>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEolz8O07Yr6uveZ9RzJeIbPvWxgxHTLLNUjEwDD_uIZ0YdWy_MmLWdNbwQt2oPgV2X3g4Tj1seMq39gMnecXLz6xLEcUhi9LsORqMubY3kOpPovo8ziY0gABtGZzSGoQrun-AL5rqwkI/s1600/Bimagic_Queen_s_Tour_on_torus_200718_WW.gif" style="margin-left: auto; margin-right: auto;"><img alt="A massive use of ±2, ±2 diagonal moves often produces a bimagic queen's tour on a torus board." border="0" data-original-height="1600" data-original-width="806" height="578" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEolz8O07Yr6uveZ9RzJeIbPvWxgxHTLLNUjEwDD_uIZ0YdWy_MmLWdNbwQt2oPgV2X3g4Tj1seMq39gMnecXLz6xLEcUhi9LsORqMubY3kOpPovo8ziY0gABtGZzSGoQrun-AL5rqwkI/s640/Bimagic_Queen_s_Tour_on_torus_200718_WW.gif" title="" width="290" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">An open queen's tour on a torus board</td></tr>
</tbody></table>
<div class="separator" style="clear: both; text-align: center;">
</div>
<br />
<h2 style="text-align: justify;">
The First Bimagic Queen's Tour</h2>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Finally, on the 23rd July 2020, after revising the selection of immutable bimagic series, the following method proved to be successful:</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
The tables below are <i>doubly-symmetric</i> arrays of immutable bimagic series, specially created for the x and y coordinates of a suitable <a href="https://carresmagiques.blogspot.com/2012/03/from-magic-square-to-magic-torus.html" target="_blank">semi-bimagic torus</a>. Arranged in groups of four, the eight colours that represent the x (file) and y (rank) coordinates can be freely attributed the values of 0 to 7:</div>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEja-bQIyRfA6A4p_dtQFwBHs1EWZYgxATGyc62AdYmwzEyHjhYXg_FuJfgVIwbMsrdql_V-PKGiUa1CwXc6QPFFJNE_zI1pmg23qkL-Cw88Usp6JKkx46mXZMtLwiVUb6XZGE6GCaZQXJk/s1600/Bimagic_Queen_s_Tour_Bimagic_Coordinates_200723_WW.gif" style="margin-left: auto; margin-right: auto;"><img alt="Doubly-symmetric arrays of immutable bimagic series, specially created for a bimagic queen's tour" border="0" data-original-height="1600" data-original-width="1021" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEja-bQIyRfA6A4p_dtQFwBHs1EWZYgxATGyc62AdYmwzEyHjhYXg_FuJfgVIwbMsrdql_V-PKGiUa1CwXc6QPFFJNE_zI1pmg23qkL-Cw88Usp6JKkx46mXZMtLwiVUb6XZGE6GCaZQXJk/s640/Bimagic_Queen_s_Tour_Bimagic_Coordinates_200723_WW.gif" title="" width="408" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Tables of coordinates for the Bimagic Queen's Tour Torus</td></tr>
</tbody></table>
<br />
<div style="text-align: justify;">
However, to construct a bimagic tour we need a regular sequence that satisfies the ±1 / ±1 diagonal constraints of regular queen's moves, and in order to make the queen's tour "converge" on the board we need to use as many ± 4, ± 4 diagonals as we can; the optimum being once every two moves. Additionally, we need to check that the x and y coordinates selected for the first eight positions of the queen will also allow for regular diagonal transitions between each quarter of N² at the moves 16-17, 32-33 and 48-49... Once these verifications are complete we can then use the approved coordinates to plot the successive positions of the queen on the semi-bimagic torus shown below, starting with the first position 1 at coordinates (0x, 0y) in the lower left-hand corner:</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><img alt="A semi-magic torus that, after translation of the board viewpoint, reveals a bimagic queen's tour" border="0" data-original-height="1600" data-original-width="1568" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0ibaiyPRryCSiyS7PIZIDG8348PU69MfsXGLJN3Im5kvcSW_VRTH8zA06zmZVXUhp6rONoi7LWtXdfLdc6Ide5KiWFksMYEGTFpz2crcXnRd7c1ifGnD5UEJQb3EuCw_wxp0WQbiiF8k/s320/Bimagic_Queen_s_Tour_Torus_Viewpoint_200723_WW.gif" style="margin-left: auto; margin-right: auto;" title="" width="220" /></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Semi-Bimagic Torus Before Translation</td></tr>
</tbody></table>
<br />
<div style="text-align: justify;">
When constructed, the semi-bimagic torus appears to only contain a broken tour; but after a translation of the 8 x 8 board viewpoint, as shown below, a complete open bimagic queen's tour is revealed:</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgRPXSRYwOeBgwrWUFHsMQFzOt1Y4_8m6xOyS4nlfI2Jn8EwnUfIAGBpTZpt4sP1r3NaCmUJYYQYVUpFcj2UPxs90ro2cGUKl9UGUnvcMtK9Y5Uf62ckHtbdIQ3j9I-7yu4R3KROw-DPMc/s1600/Bimagic_Queen_s_Tour_200723.gif" style="margin-left: auto; margin-right: auto;"><img alt="The first bimagic queen's tour and probably the first bimagic tour of any chess piece!" border="0" data-original-height="1600" data-original-width="1598" height="190" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgRPXSRYwOeBgwrWUFHsMQFzOt1Y4_8m6xOyS4nlfI2Jn8EwnUfIAGBpTZpt4sP1r3NaCmUJYYQYVUpFcj2UPxs90ro2cGUKl9UGUnvcMtK9Y5Uf62ckHtbdIQ3j9I-7yu4R3KROw-DPMc/s320/Bimagic_Queen_s_Tour_200723.gif" title="" width="190" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The First Bimagic Queen's Tour</td></tr>
</tbody></table>
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<div style="text-align: justify;">
Displaying beautiful symmetries, this is apparently not only the first bimagic queen's tour, but also the first-known bimagic tour of any chess piece!</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
In each rank and file, the orthogonal total of the successively numbered positions of the queen is the magic constant S1 = 260, and (as can be verified in the squared version below), the orthogonal total of the <i>squares</i> of the successively numbered positions of the queen is the <i>bimagic constant</i> S2 = 11180.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdtN-6FWNiWKsvgZiYZDARDyDxxZPvjlaeC4tcnJ-CQR5RkQHTcHCLXQpfCCKCqoAuugLDpRje_2kj3LDPKE5PglGSxtiwEI9w0DXR5afgtu6k4laRwAw6UuFN1dNecplh6pjE6Q-Tr7k/s1600/Bimagic_Queen_s_Tour_Squared_200723_WW.gif" style="margin-left: auto; margin-right: auto;"><img alt="The squared version of the bimagic queen's tour has an orthogonal bimagic constant of 11180." border="0" data-original-height="1600" data-original-width="1598" height="190" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdtN-6FWNiWKsvgZiYZDARDyDxxZPvjlaeC4tcnJ-CQR5RkQHTcHCLXQpfCCKCqoAuugLDpRje_2kj3LDPKE5PglGSxtiwEI9w0DXR5afgtu6k4laRwAw6UuFN1dNecplh6pjE6Q-Tr7k/s320/Bimagic_Queen_s_Tour_Squared_200723_WW.gif" title="" width="190" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Squared Bimagic Queen's Tour</td></tr>
</tbody></table>
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<div style="text-align: justify;">
Observing the bimagic queen's tour path we can see the symmetries of the four orthogonal moves (8 - 9, 24 - 25, 40 - 41, and 56 - 57). <i>Thirty-two out of the sixty-three queen's moves are </i><i>±4, </i><i>±4 diagonal</i>.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDFiHyDJdNOBRPBtAJtFV_j_UNBolrRt6ECIGpyYnM_Ygp6tIpvPr9KLMfZihrofqX5NA9T9rQQ4ZTmlgaCYwwUYVauhuEJUmJYR2u6t5b2xB1l9fSxHyKOeZrV6V5QkbkdnlrxYRb9jA/s1600/Bimagic_Queen_s_Tour_Path_200723_WW.gif" style="margin-left: auto; margin-right: auto;"><img alt="The path of the first bimagic queen's tour shows that only 4 orthogonal moves are used." border="0" data-original-height="1600" data-original-width="1592" height="190" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDFiHyDJdNOBRPBtAJtFV_j_UNBolrRt6ECIGpyYnM_Ygp6tIpvPr9KLMfZihrofqX5NA9T9rQQ4ZTmlgaCYwwUYVauhuEJUmJYR2u6t5b2xB1l9fSxHyKOeZrV6V5QkbkdnlrxYRb9jA/s320/Bimagic_Queen_s_Tour_Path_200723_WW.gif" title="" width="190" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Bimagic Queen's Tour Path</td></tr>
</tbody></table>
<h2 style="text-align: justify;">
Conclusion</h2>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
It is probable that many other examples exist, and that these will include closed bimagic queen's tours. However, it is an open question as to whether or not a <i>diagonally</i> bimagic queen's tour can be found on an 8 x 8 board! *<br />
<br />
For those who are interested, a PDF file of "A Bimagic Queen's Tour" can be downloaded <a href="https://drive.google.com/file/d/1I74v94PKSxn6vN0CiZdDECeZSNAP62Zf/view?usp=sharing" target="_blank">here</a>.</div>
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<i>* The answer to the open question has been given by Walter Trump on the 3rd August 2020. Please refer to the "Latest Developments" below!</i>
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<h2 style="text-align: justify;">
Latest Developments!<br />
</h2>
<br />
<h3>
The Answer to the Open Question!</h3>
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<div style="text-align: justify;">
On the 3rd August 2020, <a href="http://www.trump.de/magic-squares/" target="_blank">Walter Trump</a> was already able to answer the "open question" that I had formulated in my conclusion! He ran a computer check on the complete set of bimagic 8x8 squares that he had previously found with <a href="http://www.gaspalou.fr/magic-squares/index.htm" target="_blank">Francis Gaspalou</a>. Walter found that <i>on an 8x8 board there are no diagonally bimagic queen's tours </i>(or diagonally bimagic knight's tours for that matter, although it was already known that none of the 140 magic knight's tours were diagonally magic)<i>.</i> The longest possible queen's tour on a bimagic square of order-8 consists of 21 moves, as illustrated in his PDF file below:<br />
<br />
<iframe height="718px" src="https://docs.google.com/viewer?srcid=1KaS-zoRdg6Z1y4KLEUZslrhXVch8_0QA&pid=explorer&efh=false&a=v&chrome=false&embedded=true" width="518px"></iframe><br /></div>
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<div style="text-align: justify;">
<h3>
106 Bimagic Queen's Tours on an 8x8 Board!</h3>
<br />
On the 8th August 2020, testing a program that he had devised on the first bimagic queen's tour, Walter Trump found a second example, which turned out to be a complementary bimagic queen's tour. On the 11th August 2020, continuing to search with his program, Walter Trump was able to find a total of 44 closed and 62 open bimagic queen's tours!</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Walter Trump conjectures that, up to symmetry, there are no further bimagic queen's tours to be found on an 8x8 board. The program searched within the semi-bimagic 8x8 squares which were found by Walter Trump and Francis Gaspalou in 2014. Essentially different means up to symmetry and permutations of rows and columns. Unique means up to symmetry. Considering that there are more than 715 quadrillion unique semi-bimagic squares of order-8, the 106 unique queen's tours are quite rare!</div>
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<br /></div>
<div style="text-align: justify;">
These different tours are now listed and indexed in <a href="https://drive.google.com/file/d/1tQOVhq-OB37qo_ljfV5GluQdnJHNCAIq/view?usp=sharing" target="_blank">“106 Bimagic Queen’s Tours on an 8x8 Board;”</a> a paper co-authored with Walter Trump which is available below:</div>
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<iframe height="375" src="https://drive.google.com/file/d/1tQOVhq-OB37qo_ljfV5GluQdnJHNCAIq/preview" width="518"></iframe><br />
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<br />
<h3 style="text-align: justify;">
Other Publications about Bimagic Queen's Tours!</h3>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
On the 9th August 2020 <a href="http://boingboing.net/2011/10/17/interview-with-futility-closet-blogger-greg-ross.html" rel="" target="_blank">Greg Ross</a> published an article entitled <a href="https://www.futilitycloset.com/2020/08/08/a-bimagic-queens-tour/" rel="" target="_blank">"A Bimagic Queen's Tour"</a> in his excellent <a href="https://www.futilitycloset.com/2020/08/08/a-bimagic-queens-tour/" rel="" target="_blank">Futility Closet</a> - An Idler's Miscellany of Compendious Amusements. Many thanks Greg!</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
On the 24th August 2020, <a href="https://www.trump.de/magic-squares/bimagic-8/queen-tour/index.html" target="_blank">Walter Trump</a> created an excellent web page entitled <a href="https://www.trump.de/magic-squares/bimagic-8/queen-tour/index.html" target="_blank">“Closed Bimagic Queen’s Tours on an 8x8 Board”</a> which provides some interesting additional information!</div><div style="text-align: justify;"> </div><div style="text-align: justify;">On the 4th September 2020, <a href="http://www.number-galaxy.eu/" target="_blank">Bogdan Golunski</a> published <a href="http://www.number-galaxy.eu/ge_html/bimagic_on_chess_board_8x8.htm" target="_blank">510 semi-bimagic squares of order-8 with open bimagic queen's tours</a> which were calculated using a program that he had devised. His list includes rotations and reflections of the previously-known 62 open bimagic queen's tours, and although no new tours have been found, his program is shown to yield good results!</div><div style="text-align: justify;"><br /></div><div style="text-align: justify;">In a German book co-authored with <a href="https://www.uni-regensburg.de/human-sciences/educational-science-3/team/prof-dr-dr-h-c-hans-gruber/index.html" target="_blank">Hans Gruber</a>, entitled <a href="https://www.nomos-shop.de/rombach-wissenschaft/titel/schach-als-sujet-in-den-kuensten-und-der-wissenschaft-id-103592/" target="_blank">"Schach als Sujet in den Künsten und der Wissenschaft"</a>, and published on the 1st April 2022, <a href="https://en.wikipedia.org/wiki/Joachim_Br%C3%BCgge" target="_blank">Joachim Brügge</a> has included a chapter "Die erste Darstellung einer semi-bimagischen Damenwandering von William Walkington (2020)." The chapter relates the discovery of the first bimagic queen's tour, and also that of the other bimagic queen's tours on an 8x8 board which were later found by Walter Trump.</div>
<br />
<h2 style="text-align: justify;">
Acknowledgements</h2>
<br />
<div style="text-align: justify;">
I am indebted, not only to <a href="https://www.semanticscholar.org/paper/Magic-Knight's-Tours-in-Higher-Dimensions-Kumar/75e8a083e85e21855735c1964cf6992c89f8c107" target="_blank">Awani Kumar</a>, for initially bringing the subject to our attention and for his appeal for a solution, but also to <a href="https://en.wikipedia.org/wiki/Joachim_Br%C3%BCgge" target="_blank">Joachim Brügge</a>, for having had the idea of a bimagic queen's tour in the first place, and for his kind encouragements during my research. </div>
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<br /></div>
<div style="text-align: justify;">
My thanks also go to <a href="http://www.trump.de/magic-squares/bimagic-8/distribution/immutable-series.pdf" target="_blank">Dwane Campbell</a>, for publishing his findings on immutable bimagic series; series which proved so useful in the search for the bimagic queen's tour. Dwane has informed me that <a href="http://www.magichypercubes.com/Encyclopedia/" target="_blank">Aale de Winkel</a> was the first to recognize that component binary squares could be bimagic, the basis of immutable series; so my thanks to Dwane go indirectly to Aale as well.</div>
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<div style="text-align: justify;">
I am also most grateful to <a href="http://www.gaspalou.fr/magic-squares/index.htm" target="_blank">Francis Gaspalou</a>, for editing and sending our circle of magic square enthusiasts an <i>"Analysis of the 240 Immutable Series of order 8"</i> in 2018, and for sending me the full list of all 38 069 bimagic series of order-8 when I asked him for information about these in July this year.</div>
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<div class="separator" style="clear: both; text-align: center;">
<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com4tag:blogger.com,1999:blog-8742944687733483108.post-55430718322798393362020-04-30T17:18:00.003+02:002023-06-19T22:55:31.837+02:00John Horton Conway and LUX<div style="text-align: justify;">
On the 25th April 2020, I came across a newsletter of the French magazine <a href="http://www.tangente-mag.com/?" target="_blank">"Tangente"</a> announcing that, despite the ongoing COVID-19 difficulties, their next issue n° 194 would still be published at the end of May. They stated that this <a href="http://infinimath.com/librairie/abonnement-tangente-mag.php?" target="_blank">future magazine</a> would contain a main section dedicated to the late <a href="https://en.wikipedia.org/wiki/John_Horton_Conway" target="_blank">John Horton Conway</a>, famous for his <a href="https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life" target="_blank">"Game of Life"</a> (a cellular automaton in which cells live, die and are born). Having been previously unaware of Conway's death, I immediately wished to inform the fellow members of a magic square circle of the sad news, and sent them the following e-mail: </div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
<i>Dear all, </i> <i><br />
I have just learnt that John Horton Conway passed away on the 11th April in New Brunswick, New Jersey, at the age of 82, after complications from COVID-19. I did not know him personally, but I expect that some of you did. His well-known LUX method for magic squares is an algorithm for creating magic squares of order 4n+2, where n is a natural number, and his "lozenge" method is another method of construction of magic squares. So this is a considerable loss to the magic square community, and goes to show that the virus is indiscriminate and dangerous. </i> <i><br />
Here's hoping that a cure will be found soon. </i> <i><br />
Stay safe! </i> <i><br />
William </i></div>
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<div style="text-align: justify;">
<div style="text-align: justify;">
I rapidly received replies from <a href="https://arxiv.org/search/math?query=Loly%2C+Peter&searchtype=author&abstracts=show&order=-announced_date_first&size=50" target="_blank">Peter Loly</a>, <a href="https://arxiv.org/search/cond-mat?searchtype=author&query=Ziff%2C+R+M" target="_blank">Bob Ziff</a>, <a href="https://arxiv.org/search/math?query=Kumar%2C+Awani&searchtype=author&abstracts=show&order=-announced_date_first&size=50" target="_blank">Awani Kumar</a> and <a href="http://www.multimagie.com/AmelaUHIMS.pdf" target="_blank">Miguel Angel Amela</a>:</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Peter Loly stated that Conway's passing away reminded him of his colleague <a href="https://science.ucalgary.ca/mathematics-statistics/about/richard-guy" target="_blank">Richard Guy</a> who had passed away aged 103 on the 30th September 2019, and also of the losses of <a href="https://en.wikipedia.org/wiki/John_R._Hendricks" target="_blank">John Hendricks</a> and <a href="http://www.multimagie.com/English/Heinz.htm" target="_blank">Harvey Heinz</a>, both of whom he had met. He asked if I could send this information out on the blog.</div>
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<br /></div>
<div style="text-align: justify;">
Bob Ziff replied to say that Conway had had the bad luck of being in a nursing home for some other health problems, and concluded by writing <i>"Let’s all hope that we stay healthy!"</i></div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Awani Kumar replied with a simple <i>"So sad. RIP."</i></div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Miguel Angel Amela then replied with a photomontage of a very fitting "in memoriam" plaque: He proposed that John Horton Conway's name could be inscribed above a 6x6 magic square constructed with Conway's <a href="https://en.wikipedia.org/wiki/Conway%27s_LUX_method_for_magic_squares" target="_blank">LUX method</a>, and that the Spanish words "descansa en la LUX" could be inscribed below. The Spanish text<i> "descansa en la LUX"</i> means <i>"rest in the LUX"</i> or <i>"rest in the LIGHT."</i> Miguel stated that in Latin, the inscription would be <i>R.I.L.</i> or <i>"</i><span lang="EN-GB"><i>REQUIESCAT IN LUX,"</i> and he suggested a poem written by </span><span lang="EN-GB"><span lang="EN-GB">Art Durkee, </span>entitled <a href="http://artdurkee.blogspot.com/2009/02/requiescat-in-lux.html" target="_blank">"requiescat in lux."</a> </span><br />
<br /></div>
<h2 style="text-align: justify;">
An "In Memoriam" plaque for John Horton Conway</h2>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjucR-21nSHvyz_G-vapkvqyfWczsJeWbb9RaSZWNRxT-wqtC80JSGj4ryPdDBxmUWrJtc8gQxWvv2dEdXNAow7fOYY-de-ill1JKQMSUUJ7ZRv8oEnjme1xM8s_nQ_8McF7zZo6FQuLoY/s1600/John-Horton-Conway-LUX-Memorial-Plaque.png" style="margin-left: auto; margin-right: auto;"><img alt="Miguel Amela's idea of an "in memoriam" plaque in homage of John Horton Conway and his LUX method for constructing magic squares" border="0" data-original-height="839" data-original-width="1600" height="228" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjucR-21nSHvyz_G-vapkvqyfWczsJeWbb9RaSZWNRxT-wqtC80JSGj4ryPdDBxmUWrJtc8gQxWvv2dEdXNAow7fOYY-de-ill1JKQMSUUJ7ZRv8oEnjme1xM8s_nQ_8McF7zZo6FQuLoY/s640/John-Horton-Conway-LUX-Memorial-Plaque.png" title="" width="512" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Adaptation of Miguel Angel Amela's idea of an "in memoriam" plaque for John Horton Conway</span></td></tr>
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Perhaps, one day, a plaque like this will be placed at Cambridge or Princeton, or at another of Conway's haunts.<br />
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<span lang="EN-GB">John Horton Conway's LUX Method</span></h2>
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<span lang="EN-GB"><a href="https://sites.google.com/site/martinerickson/" target="_blank">Martin Erickson</a> has already described Conway's LUX method in page 98 of <a href="https://books.google.fr/books?id=ywKyQz7_4-MC&pg=PA98&redir_esc=y#v=onepage&q&f=false" target="_blank">"Aha Solutions"</a> (published by the Mathematical Association of America in 2009), </span><i>and he even used the same "in memoriam" square of order-6 as a base array to construct a LUX square of order-18!</i> However, here it is useful to examine how the LUX method can be used to construct the "in memoriam" square itself, and the following pdf file explains the construction steps:</div>
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<iframe height="410" src="https://drive.google.com/file/d/1vp8ffZ7wW8GX81KatM7KiDacx3U9Lkam/preview" width="518"></iframe><br />
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The "in memoriam" magic square can also be programmed, for example using languages such as <a href="https://rosettacode.org/wiki/Category:Elixir" target="_blank">Elixir,</a> <a href="https://rosettacode.org/wiki/Category:Haskell" target="_blank">Haskell</a> and <a href="https://rosettacode.org/wiki/Category:Ruby" target="_blank">Ruby,</a> as shown in <a href="https://rosettacode.org/wiki/Magic_squares_of_singly_even_order" target="_blank">"Magic squares of singly even order,"</a> edited by the programming chrestomathy site <a href="http://rosettacode.org/wiki/Rosetta_Code" target="_blank">"Rosetta Code."</a></div>
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Conclusions</h2>
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This short article only intends to commemorate a small part of John Horton Conway's work on magic squares. Because I myself have never had the pleasure of meeting him, those who did are far better placed to write about his other accomplishments, and about his life in general. The <a href="https://www.princeton.edu/news/2020/04/14/mathematician-john-horton-conway-magical-genius-known-inventing-game-life-dies-age" target="_blank">obituary</a> written by <a href="https://research.princeton.edu/people/catherine-zandonella" target="_blank">Catherine Zandonella</a> for Princeton University gives us a good insight, not only of his many achievements, but also of his mathematical playfulness and of his kind attention to others that made him many friends. Another source of information with useful external links is <a href="http://mathshistory.st-andrews.ac.uk/Biographies/Conway.html" target="_blank">John Horton Conway's biography</a> written by <a href="https://risweb.st-andrews.ac.uk/portal/en/persons/john-joseph-oconnor(d8ca4d9f-4b1b-4627-93f9-c035fa1e1b6c).html" target="_blank">John Joseph O'Connor</a> and <a href="http://www-groups.mcs.st-andrews.ac.uk/~edmund/" target="_blank">Edmund Frederick Robertson</a> for the MacTutor History of Mathematics Archive at the University of St Andrews. </div>
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Acknowledgements</h2>
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I wish to thank <a href="https://arxiv.org/search/math?query=Loly%2C+Peter&searchtype=author&abstracts=show&order=-announced_date_first&size=50" target="_blank">Peter Loly</a>, <a href="https://arxiv.org/search/cond-mat?searchtype=author&query=Ziff%2C+R+M" target="_blank">Bob Ziff</a>, <a href="https://arxiv.org/search/math?query=Kumar%2C+Awani&searchtype=author&abstracts=show&order=-announced_date_first&size=50" target="_blank">Awani Kumar</a> and <a href="http://www.multimagie.com/AmelaUHIMS.pdf" target="_blank">Miguel Angel Amela</a> for replying to my e-mail. Their messages and contributions have inspired me to write this post.</div>
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With COVID-19 still active and dangerous at the time of writing, I urge you all to take heed of the social distancing guidelines, and keep safe!</div>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-45909618566551106652020-03-01T19:32:00.003+01:002023-06-19T22:56:14.632+02:00A Tetrad Puzzle<div style="text-align: justify;">My recent interest in tetrads has been sparked off by an article entitled <a href="https://www.pourlascience.fr/sd/mathematiques/combines-pour-tetrades-18708.php" rel="" target="_blank">"Combines pour Tétrades,"</a> that was written by <a href="https://en.wikipedia.org/wiki/Jean-Paul_Delahaye" rel="" target="_blank">Professor Jean-Paul Delahaye</a>, and published in the January 2020 edition of the magazine Pour La Science (N° 507). </div><div style="text-align: justify;"><br />
An interesting conversation ensued with my friend <a href="https://en.wikipedia.org/wiki/Walter_Trump" rel="" target="_blank">Walter Trump</a>, who, having already done pioneer work on the subject since 1970, then decided in February 2020 to create his own specialised website <a href="https://www.trump.de/tetrads/" rel="" target="_blank">"Further Questions About Tetrads."</a> Here he gives a step-by-step analysis and relates his own tetrad story. For readers who wish to learn more about tetrads and their history, I thoroughly recommend this site, which not only gives clear explanations, but also includes an exhaustive list of references.</div><br />
<h3 style="text-align: justify;">Definition of a Tetrad</h3><br />
<div style="text-align: justify;">According to <a href="https://en.wikipedia.org/wiki/Martin_Gardner" rel="" target="_blank">Martin Gardner</a>, in page 121 of his 1989 book <a href="https://epdf.pub/penrose-tiles-to-trapdoor-ciphers-and-the-return-of-dr-matrix-spectrum-series.html" rel="" target="_blank">"Penrose Tiles to Trapdoor Ciphers ...and the Return of Dr. Matrix,"</a> it was Michael R.W. Buckley, who, in the Journal of Recreational Mathematics (1975, Vol. 8), was the first to propose the name tetrad, for four simply connected planar regions, each pair of which sharing a finite portion of a common boundary.<br />
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Here, we will only be considering tetrads with <a href="https://en.wikipedia.org/wiki/Congruence_(geometry)" rel="" target="_blank">congruent</a> regions, each of which being transformable into each other by a combination of rigid motions that include translation, rotation, and reflection.<br />
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The following definition therefore applies: Tetrads are constituted of four congruent regions, when each of which shares a finite portion of their boundary with each of the others. </div><br />
<h3 style="text-align: justify;">Tetrads Published in Martin Gardner's "Mathematical Games" Column</h3><br />
<div style="text-align: justify;">In his "Mathematical Games" column for Scientific American, Martin Gardner wrote a Problem 7.8 entitled "Exploring Tetrads," and illustrated <a href="https://archive.org/details/B-001-001-266/page/n191/mode/1up" rel="" target="_blank">several tetrad examples in Figure 7.11</a>. The part D of this Figure 7.11 showed a 22-sided polygonal tetrad solution with congruent pieces that had bilateral symmetry and a bilaterally symmetric border. Martin Gardner asked if an alternative solution might exist, with polygons of fewer sides.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">In the Answer 7.8 that appeared in the "Mathematical Games" column of April 1977, Martin Gardner stated that Robert Ammann, Greg Frederickson and Jean L. Loyer had each found an 18-sided polygonal tetrad with bilateral symmetry, thus improving on the 22-sided solution that he had previously published. <a href="https://archive.org/details/B-001-001-266/page/n208/mode/1up" rel="" target="_blank">The Ammann-Frederickson-Loyer solution, illustrated in Figure 7.33</a>, is the smallest holeless tetrad that can made from a polyiamond with mirror symmetry. We can see that each of the four pieces of this tetrad share a common boundary with each of the others. This assembly can be achieved by the translation or the rotation of copies of a starting piece. Although reflection is also possible, no reflection of the pieces is necessary for the construction of the tetrad. </div><br />
<h2 style="text-align: justify;">Tetrad Puzzle Transformations</h2><br />
<div style="text-align: justify;">While examining the different tetrads that have already been found, I noticed that some of these puzzles have completely interlocking pieces, whilst others do not. This gave me the idea of searching for jigsaw piece assemblies.</div><br />
<div style="text-align: justify;">The following 5 propositions are transformations of the bilaterally symmetric tetrad found by Robert Ammann, Greg Frederickson and Jean L. Loyer. The addition of tabs, and the subtraction of blanks, can cause the jigsaw puzzle pieces to become<i> asymmetric</i>. Also, during the design process, we can decide whether or not certain pieces have to be flipped over, (reflected), in order to construct the tetrad:</div><br />
<h3 style="text-align: justify;">1/ Assembly of Simple Tetrad Jigsaw Puzzle Pieces, with 3 Tabs and 3 Blanks</h3><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWQiDNPBD7Tdy8gqmtP9-q_F3kNm6kNeBLzggSgfUjXk0jwuaWycNxGMm5LJuS7LvukzQRmPB2sji9AhUupFMzYmcFCFCnLKzEsdX4V2vlihJgIMTpd-L-JJeaQZTMvUASHm_u_AE9HdU/s1600/tetrad_puzzle_1a_WW_og.png" style="margin-left: auto; margin-right: auto;"><img alt="Simple congruent tetrad jigsaw puzzle pieces make a holeless tetrad." border="0" data-original-height="837" data-original-width="1600" height="239" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWQiDNPBD7Tdy8gqmtP9-q_F3kNm6kNeBLzggSgfUjXk0jwuaWycNxGMm5LJuS7LvukzQRmPB2sji9AhUupFMzYmcFCFCnLKzEsdX4V2vlihJgIMTpd-L-JJeaQZTMvUASHm_u_AE9HdU/s400/tetrad_puzzle_1a_WW_og.png" title="" width="460" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Tetrad Jigsaw Puzzle n°1 making a holeless tetrad: Solution n°1a.</span></td></tr>
</tbody></table><div class="separator" style="clear: both; text-align: center;"></div><div style="text-align: justify;">In this first solution, which is a holeless tetrad, the pieces are not just translations and/or rotations of each other: Supposing that the starting piece is yellow, <i>the pink and blue pieces are also reflected.</i></div><br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjnNihvH10U0dVyEBusvpY_gGh5WbGE3pzi2x7fAnNcWce3zmRTb2k42DarNG_zai2mpZFB-VHAxkMuxs7aqQbWLsLUpOyqnvMQQk_ioWyALVPKay5lJCsE7D1B2QMv3NQA91FeFVYWGY4/s1600/tetrad_puzzle_1b_WW.png" style="margin-left: auto; margin-right: auto;"><img alt="Simple congruent tetrad jigsaw puzzle pieces make a tetrad with a hole." border="0" data-original-height="1412" data-original-width="1600" height="282" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjnNihvH10U0dVyEBusvpY_gGh5WbGE3pzi2x7fAnNcWce3zmRTb2k42DarNG_zai2mpZFB-VHAxkMuxs7aqQbWLsLUpOyqnvMQQk_ioWyALVPKay5lJCsE7D1B2QMv3NQA91FeFVYWGY4/s320/tetrad_puzzle_1b_WW.png" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Tetrad Jigsaw Puzzle n°1 making a tetrad with a hole: Solution n°1b.</span></td></tr>
</tbody></table><div style="text-align: justify;">In this second solution, which is a tetrad with a hole, the pieces are always translations and/or rotations of each other.</div><br />
<h3 style="text-align: justify;">2/ Assembly of Tetrad Jigsaw Puzzle Pieces, with 10 Tabs and 8 Blanks</h3><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhFiqQLPd6NDAwd9TC3PzQ7E5mHULpOCv2Nb3zRXX3vd6ic63fxBEjBiC_up5Da4DpDux5gpBF_1n64Pjavscl3jlZmeg2tds93QCzzkrVn58Z8XvgwkbdrPqrMwBcERlG0F05QRMzw2Kw/s1600/tetrad_puzzle_2a_WW.png" style="margin-left: auto; margin-right: auto;"><img alt="Congruent jigsaw puzzle pieces with 10 tabs and 8 blanks make this holeless tetrad." border="0" data-original-height="1143" data-original-width="1600" height="228" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhFiqQLPd6NDAwd9TC3PzQ7E5mHULpOCv2Nb3zRXX3vd6ic63fxBEjBiC_up5Da4DpDux5gpBF_1n64Pjavscl3jlZmeg2tds93QCzzkrVn58Z8XvgwkbdrPqrMwBcERlG0F05QRMzw2Kw/s320/tetrad_puzzle_2a_WW.png" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Tetrad Jigsaw Puzzle n°2 making a holeless tetrad: Solution n°2a.</span></td></tr>
</tbody></table><div style="text-align: justify;">In this first solution, which is a holeless tetrad, the pieces are always translations and/or rotations of each other<i>.</i></div><br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSYan_QxtKHAS9yuLkQWUvygGV_6wta9c-sxDUcpiEk8F1TBe4EmOY3dysAObQFXNyh5ATy9hMVgNaiA4mrEhyphenhyphenx-ITUxUbaRXddFZYRiGN_dSPpVAARxUENV5raY2N_Eytfu7LfVUBFI8/s1600/tetrad_puzzle_2b_WW.png" style="margin-left: auto; margin-right: auto;"><img alt="Congruent jigsaw puzzle pieces with 10 tabs and 8 blanks make this tetrad with a hole." border="0" data-original-height="1418" data-original-width="1600" height="283" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSYan_QxtKHAS9yuLkQWUvygGV_6wta9c-sxDUcpiEk8F1TBe4EmOY3dysAObQFXNyh5ATy9hMVgNaiA4mrEhyphenhyphenx-ITUxUbaRXddFZYRiGN_dSPpVAARxUENV5raY2N_Eytfu7LfVUBFI8/s320/tetrad_puzzle_2b_WW.png" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Tetrad Jigsaw Puzzle n°2 making a tetrad with a hole: Solution n°2b.</span></td><td class="tr-caption" style="text-align: center;"><br /></td><td class="tr-caption" style="text-align: center;"><br /></td></tr>
</tbody></table><div style="text-align: justify;">In this second solution, which is a tetrad with a hole, the pieces are always translations and/or rotations of each other.</div><br />
<h3 style="text-align: justify;">3/ Assembly of Tetrad Jigsaw Puzzle Pieces, with 18 Alternate Tabs and Blanks</h3><br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbvMXdfa3Zk8HpW6OFnv0C64bmaBNM6FbsDxGbTRXJC-_y9RUbLSU52vccg24TkKWk6hGEV4xXBK0EhzvLbdhqjZyy_JIFBOo1vwmXppzyY6c12R-z_iGWki3RRzjzqc8m_DFhQgue_v4/s1600/tetrad_puzzle_3a_WW.png" style="margin-left: auto; margin-right: auto;"><img alt="Congruent jigsaw puzzle pieces with 18 alternating tabs and blanks make this holeless tetrad." border="0" data-original-height="1137" data-original-width="1600" height="227" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbvMXdfa3Zk8HpW6OFnv0C64bmaBNM6FbsDxGbTRXJC-_y9RUbLSU52vccg24TkKWk6hGEV4xXBK0EhzvLbdhqjZyy_JIFBOo1vwmXppzyY6c12R-z_iGWki3RRzjzqc8m_DFhQgue_v4/s320/tetrad_puzzle_3a_WW.png" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Tetrad Jigsaw Puzzle n°3 making a holeless tetrad: Solution n°3a.</span></td></tr>
</tbody></table><div style="text-align: justify;">In this first solution, which is a holeless tetrad, the pieces are not just translations and/or rotations of each other: Supposing that the starting piece is yellow, <i>the green piece is also reflected.</i></div><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqozkP4ep1tMe6bWFaFX7vuU6VXjvC3-FtwHovflkMMnZuNY8YX8ber6elnB-DSdwnWl2PxWNdFTkH7eeE1C0CHaAusK4ctORwq_4J3wdJv5h3jixhgw7hcDMXbgVQR6phIuFdvbVpZ3A/s1600/tetrad_puzzle_3b_WW.png" style="margin-left: auto; margin-right: auto;"><img alt="Congruent jigsaw puzzle pieces with 18 alternating tabs and blanks make this tetrad with a hole." border="0" data-original-height="1425" data-original-width="1600" height="284" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqozkP4ep1tMe6bWFaFX7vuU6VXjvC3-FtwHovflkMMnZuNY8YX8ber6elnB-DSdwnWl2PxWNdFTkH7eeE1C0CHaAusK4ctORwq_4J3wdJv5h3jixhgw7hcDMXbgVQR6phIuFdvbVpZ3A/s320/tetrad_puzzle_3b_WW.png" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Tetrad Jigsaw Puzzle n°3 making a tetrad with a hole: Solution n°3b.</span></td></tr>
</tbody></table><div style="text-align: justify;">In this second solution, which is a tetrad with a hole, the pieces are not just translations and/or rotations of each other: Supposing that the starting piece is yellow, <i>the green piece is also reflected.</i></div><br />
<h3 style="text-align: justify;"><i>Observation on the limitations of tetrad puzzle pieces with tabs and blanks</i></h3><br />
<div style="text-align: justify;">When using jigsaw puzzle pieces, <i>unless the sizes of the tabs and blanks are considerably reduced</i>, conflicting graphics can sometimes occur in acute angles. However, it is possible to get round this difficulty by using plus (+) signs instead of tabs, and minus (-) signs instead of blanks, as shown in the examples that follow:</div><br />
<h3 style="text-align: justify;">4/ Assembly of Tetrad Jigsaw Puzzle Pieces, with 9 Positives and 9 Negatives</h3><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2rEEX42hMfAbjLd0kUMf4ad-uGjK8TtmCV1n3OXBzI5RpdiMBkJinwJQfWQwsDbsAg3Syb42QfDmpQi-XL71l073SfvcoF8_EZ2g69fZvXPkPt9-e1MaCDqxzLQ2F6Y3qE3RciWh2oto/s1600/tetrad_puzzle_4a_WW.png" style="margin-left: auto; margin-right: auto;"><img alt="Congruent jigsaw puzzle pieces with 9 positives and 9 negatives make this holeless tetrad." border="0" data-original-height="1133" data-original-width="1600" height="226" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2rEEX42hMfAbjLd0kUMf4ad-uGjK8TtmCV1n3OXBzI5RpdiMBkJinwJQfWQwsDbsAg3Syb42QfDmpQi-XL71l073SfvcoF8_EZ2g69fZvXPkPt9-e1MaCDqxzLQ2F6Y3qE3RciWh2oto/s320/tetrad_puzzle_4a_WW.png" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Tetrad Jigsaw Puzzle n°4 making a holeless tetrad: Solution n°4a.</span></td></tr>
</tbody></table><div style="text-align: justify;">In this first solution, which is a holeless tetrad, the pieces are not just translations and/or rotations of each other: Supposing that the starting piece is yellow, <i>the blue and pink pieces are also reflected.</i></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjMLRdcV14Mvc_sCRdC2_igHubvWd0Yy1wm1zCgOlLcAO5GCSyZ9_mv4mN1YtpM9Fcw8_XIMInELLWs2qAQdYqIGW0TaUVUeFAzz4aInMwbpD-KLqcL_0A6q-wkNQ2Ux0VXfGyShzkHcY/s1600/tetrad_puzzle_4b_WW.png" style="margin-left: auto; margin-right: auto;"><img alt="Congruent jigsaw puzzle pieces with 9 positives and 9 negatives make this tetrad with a hole." border="0" data-original-height="1415" data-original-width="1600" height="283" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjMLRdcV14Mvc_sCRdC2_igHubvWd0Yy1wm1zCgOlLcAO5GCSyZ9_mv4mN1YtpM9Fcw8_XIMInELLWs2qAQdYqIGW0TaUVUeFAzz4aInMwbpD-KLqcL_0A6q-wkNQ2Ux0VXfGyShzkHcY/s320/tetrad_puzzle_4b_WW.png" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Tetrad Jigsaw Puzzle n°4 making a tetrad with a hole: Solution n°4b.</span></td><td class="tr-caption" style="text-align: center;"><br /></td></tr>
</tbody></table><div style="text-align: justify;">In this second solution, which is a tetrad with a hole, the pieces are always translations and/or rotations of each other<i>.</i></div><br />
<h3 style="text-align: justify;">5/ Assembly of Tetrad Jigsaw Puzzle Pieces, with 10 Positives and 8 Negatives</h3><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEihMYijkIySQL74HTA1XUbh5hlfsPvvhw6CeDXMHND8ER9ptl__doNivoM-kTT62x2_TnFR7gAHf8Whh09Hxqc8m0fuVYYgmIx4uCdjmcdMX5m6DlxIr1G-KJWbYi1PIza65anzPiq4_JE/s1600/tetrad_puzzle_5a_WW.png" style="margin-left: auto; margin-right: auto;"><img alt="Congruent jigsaw puzzle pieces with 10 positives and 8 negatives make this holeless tetrad." border="0" data-original-height="1141" data-original-width="1600" height="228" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEihMYijkIySQL74HTA1XUbh5hlfsPvvhw6CeDXMHND8ER9ptl__doNivoM-kTT62x2_TnFR7gAHf8Whh09Hxqc8m0fuVYYgmIx4uCdjmcdMX5m6DlxIr1G-KJWbYi1PIza65anzPiq4_JE/s320/tetrad_puzzle_5a_WW.png" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Tetrad Jigsaw Puzzle n°5 making a holeless tetrad: Solution n°5a.</span></td></tr>
</tbody></table><div style="text-align: justify;">In this first solution, which is a holeless tetrad, the pieces are not just translations and/or rotations of each other: Supposing that the starting piece is yellow, <i>the blue, green and pink pieces are also reflected.</i></div><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhpMYOC3fWjVbS1UwhUeFLEC08eiD2xOcbdCyMCdvhLoLExZEHKHv6B1w2qB66_GOfiGPEBRpan72VNvOhB9FKDW_zV3ByNon2vIU5H4dHC8CHPXtH1o6-h5vIP9K833UO24PVzaWdEI-E/s1600/tetrad_puzzle_5b_WW.png" style="margin-left: auto; margin-right: auto;"><img alt="Congruent jigsaw puzzle pieces with 10 positives and 8 negatives make this tetrad with a hole." border="0" data-original-height="1427" data-original-width="1600" height="285" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhpMYOC3fWjVbS1UwhUeFLEC08eiD2xOcbdCyMCdvhLoLExZEHKHv6B1w2qB66_GOfiGPEBRpan72VNvOhB9FKDW_zV3ByNon2vIU5H4dHC8CHPXtH1o6-h5vIP9K833UO24PVzaWdEI-E/s320/tetrad_puzzle_5b_WW.png" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Tetrad Jigsaw Puzzle n°5 making a tetrad with a hole: Solution n°5b.</span></td></tr>
</tbody></table><div style="text-align: justify;">In this second solution, which is a tetrad with a hole, the pieces are not just translations and/or rotations of each other: Supposing that the starting piece is yellow, <i>the green piece is also reflected.</i><br />
<br />
<h2>Observations</h2><br />
The necessary congruence of tetrad pieces implies that each can be transformed into each other by a combination of rigid motions which include translation, rotation, and reflection. The tetrad jigsaw puzzle exercises presented above show that, depending on the arrangement of the tabs and blanks of the pieces, reflection is sometimes, but not always needed, in order to achieve the correct assembly.<br />
<br />
There could be a case for a new sub-classification of tetrads in general, depending on whether or not a reflection of their components is required.<br />
<br />
In the examples given above we notice that there are jigsaw puzzle piece solutions with 9 tabs (+) and 9 blanks (-), with 10 tabs (+) and 8 blanks (-), or with 8 tabs (+) and 10 blanks (-). Why do these differences occur? The <a href="https://drive.google.com/file/d/1gKsMTnPZlbJ3_fwDMIWgH7VvyEdqacB3/preview" rel="" target="_blank">following document</a> is an analysis of the different combinations of the positives (+) and negatives (-) of the tetrad puzzle pieces, depending the choices made during the design process:<br />
<br />
<iframe src='https://drive.google.com/file/d/1gKsMTnPZlbJ3_fwDMIWgH7VvyEdqacB3/preview' width='518' height='375'></iframe>
<br />
<br />
We can also construct other shapes that are not necessarily tetrads. Readers who are interested, are invited to explore the many possibilities, and create their own patterns.<br />
<br />
<h2>Acknowledgements</h2><br />
I wish to thank <a href="https://oeis.org/wiki/User:Craig_Knecht" rel="" target="_blank">Craig Knecht</a> and <a href="https://en.wikipedia.org/wiki/Walter_Trump" rel="" target="_blank">Walter Trump</a> for their encouragements and useful comments during the preparatory phase of this post. </div><div style="clear: both;"></div>
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<div class="separator" style="clear: both; text-align: center;">
<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-6983321747988480402019-09-14T17:46:00.006+02:002023-06-19T22:57:04.007+02:00List of the 880 Frénicle Magic Squares of Order-4<div style="text-align: justify;">
<a href="https://en.wikipedia.org/wiki/Bernard_Fr%C3%A9nicle_de_Bessy" rel="" target="_blank">Bernard Frénicle de Bessy</a> was the first to determine that there were 880 essentially different magic squares of order-4, and his findings were published posthumously in the <a href="https://babel.hathitrust.org/cgi/pt?id=ucm.5323750390&view=image&seq=498" rel="" target="_blank">"Table Générale des Quarrez Magiques de Quatre,"</a> in 1693.</div>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjo3W591dPKzco_JXGVEqhLEIyPg1EE2L8zOKwhq6-2S1lDzLUw-MoGpuc7vH0EvFRMbwL64gw_wNuHdWIs8uLuig76jtYJ73jua59fqqF_dgU6A9d0mnMlLPnSSUZ_dWM8bjoWcvEG4jU/s1600/DES-QUARREZ-OU-TABLES-MAGIQUES_og.png" style="margin-left: auto; margin-right: auto;"><img alt="Title from "Divers ouvrages de mathematique et de physique / par Messieurs de l'Académie Royale des Sciences [M. de Frénicle ... et al.]."" border="0" data-original-height="316" data-original-width="607" height="181" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjo3W591dPKzco_JXGVEqhLEIyPg1EE2L8zOKwhq6-2S1lDzLUw-MoGpuc7vH0EvFRMbwL64gw_wNuHdWIs8uLuig76jtYJ73jua59fqqF_dgU6A9d0mnMlLPnSSUZ_dWM8bjoWcvEG4jU/s320/DES-QUARREZ-OU-TABLES-MAGIQUES_og.png" title="" width="350" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><a href="http://babel.hathitrust.org/cgi/pt?u=1&num=423&seq=11&view=image&size=100&id=ucm.5323750390" rel="" target="_blank">Title of Frénicle's study of magic squares published in 1693</a></span></td></tr></tbody></table>
<i></i>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDBgc_3jRBFjFPaWH0S8HqfstWGWRv95SBTOOBhbt-01fzqx1QMtiJza-2bLfWaZ3pMbPSm8X8M5Qj3gpDrMNsITJwPzaNCIMUkqDhKneA6fjNp5UW-MHFm5Tdogs6_Yp22C3M6a-ipYg/s1600/TABLE_GENERALE_DES_QUARREZ_.png" style="margin-left: auto; margin-right: auto;"><img alt="This is the first page of the Table General of Magic Squares of Order-4 by Bernard Frénicle de Bessy" border="0" data-original-height="392" data-original-width="585" height="214" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDBgc_3jRBFjFPaWH0S8HqfstWGWRv95SBTOOBhbt-01fzqx1QMtiJza-2bLfWaZ3pMbPSm8X8M5Qj3gpDrMNsITJwPzaNCIMUkqDhKneA6fjNp5UW-MHFm5Tdogs6_Yp22C3M6a-ipYg/s320/TABLE_GENERALE_DES_QUARREZ_.png" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><a href="https://babel.hathitrust.org/cgi/pt?id=ucm.5323750390&view=image&seq=498" rel="" target="_blank">The "Table Générale des Quarrez Magiques de Quatre" published in 1693</a></span></td></tr>
</tbody></table>
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<div style="text-align: justify;">
It was more than 300 years later, that it was discovered that these 880 magic squares of order-4 were displayed on <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">255 magic tori of order-4</a>. At first listed by type in 2011, the 255 magic tori of order-4 were later given additional index numbers in a <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" rel="" target="_blank">"Table of Fourth-Order Magic Tori"</a> in 2012. Then in 2018, it was found that the 255 magic tori came from <a href="https://drive.google.com/file/d/1CLhck41V8LwIzfrqRRvAArqDsEeVEZ0F/view" rel="" target="_blank">82 multiplicative magic tori of order-4</a>. In 2019 some of the magic tori of order-4 were found to be <a href="https://carresmagiques.blogspot.com/2020/04/extra-magic-tori-and-knight-move-magic-diagonals.html" target="_blank">extra-magic</a>, with nodal intersections of 4 or more magic lines and / or knight move magic diagonals. Other studies of the magic tori of order-4 have included <a href="https://carresmagiques.blogspot.com/2013/03/1920-sub-magic-squares-on-255-4th-order.html" target="_blank">sub-magic 2 x 2 squares</a> (in 2013), <a href="https://carresmagiques.blogspot.com/2020/04/self-complementary-magic-tori-order-4.html" target="_blank">magic torus complementary number patterns</a> (in 2017), and <a href="https://carresmagiques.blogspot.com/2020/04/even-and-odd-number-patterns-on-magic-tori.html" target="_blank">even and odd number patterns</a> (in 2019). </div>
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<div style="text-align: justify;">
It has become increasingly important to provide an easily accessible document that recapitulates these different findings. I have therefore compiled the following <a href="https://drive.google.com/file/d/1bwUop4KG4QCkI3VhzFavyMx_10wMwoJF/view?usp=sharing" rel="" target="_blank">"List of the 880 Frénicle Indexed Magic Squares of Order-4,"</a> with their corresponding <a href="https://archive.org/details/AmusementsInMathematicspdf/page/n175/mode/2up?" rel="" target="_blank">Dudeney types</a><a href="https://archive.org/details/AmusementsInMathematicspdf/page/n175/mode/2up?"> </a>and also full details of the magic tori:</div>
<br />
<iframe height="710px" src="https://docs.google.com/viewer?srcid=1bwUop4KG4QCkI3VhzFavyMx_10wMwoJF&pid=explorer&efh=false&a=v&chrome=false&embedded=true" width="518px"></iframe>
<br />
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<div class="separator" style="clear: both; text-align: center;">
<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-32482011420188817532019-09-02T17:23:00.004+02:002023-06-19T22:57:40.407+02:00Even and Odd Number Patterns on Magic Tori of Orders 3 and 4<div style="text-align: justify;">Ancient references to the pattern of even and odd numbers of the 3 × 3 magic square appear in the <a href="https://en.wikipedia.org/wiki/I_Ching" rel="" target="_blank">"I Ching"</a> or "Yih King" (Book of Changes). In the introduction to the Chou edition, the scroll of the river Loh or "Loh-Shu", which is represented by the magic square of order-3, is written with black dots (the yin symbol and emblem of earth) for the even numbers, and white dots (the yang symbol and emblem of heaven) for the odd numbers. The <a href="http://baharna.com/iching/articles/river_trigrams.html#LuoshuLoRiverWriting" rel="nofollow" target="_blank">"Loh-Shu"</a> is incorporated in the writings of Ts'ai Yuän-Ting who lived from 1135 to 1198:<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhu0imAoCLUx2yYkjLF2EI4gTihgLLEnmaHZ4prWp5MjwmYfm6UbBqo0gc7tNDG1SD30RBRfP1Q4m_r4N4cAm9WoDKB1iTS9qNxfcLPk9QXmP-0dWUuMDEZiiYhA_2vq7SVigdMPgAzGi4/s1600/Lo-Shu_og.png" style="margin-left: auto; margin-right: auto;"><img alt="The Scroll of Loh is an ancient drawing of the 3x3 magic square by Ts'ai Yuän-Ting." border="0" data-original-height="311" data-original-width="591" height="168" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhu0imAoCLUx2yYkjLF2EI4gTihgLLEnmaHZ4prWp5MjwmYfm6UbBqo0gc7tNDG1SD30RBRfP1Q4m_r4N4cAm9WoDKB1iTS9qNxfcLPk9QXmP-0dWUuMDEZiiYhA_2vq7SVigdMPgAzGi4/s320/Lo-Shu_og.png" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The Scroll of Loh, according to Ts'ai Yüang-Ting</span></td></tr>
</tbody></table></div><br />
<div style="text-align: justify;">A <a href="https://en.wikipedia.org/wiki/Magic_square#normal_magic_square" rel="" target="_blank">normal</a> <a href="https://carresmagiques.blogspot.com/2012/03/from-magic-square-to-magic-torus.html" target="_blank">magic torus</a> (or magic square) of <i>order-n</i> uses consecutive numbers from <i>1 to n²</i> and consequently, for the <i>order-3</i>, the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> <i>(MC) = 15</i>. The Loh-Shu Magic Torus of Order-3 is presented below, together with its corresponding even and odd number pattern P3:</div><br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAohh6WE07CyvhZrMRmMBaRhaFFXWBNXfTSr4o7Rcxd9l1EUOtsuzfuZATfmCgyWbqOlDAhfXSf8Zt4VwOInBGzzKn1ssAHHOx9P9Ahienw3fQhX2hiX7osm5UaavWF4tkJkr1VsB6OJ8/s1600/Magic_Torus_Order-3_even_odd_number_pattern_P3.png" style="margin-left: auto; margin-right: auto;"><img alt="The magic torus or magic square of order-3 and its even and odd number pattern P3." border="0" data-original-height="763" data-original-width="1600" height="190" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAohh6WE07CyvhZrMRmMBaRhaFFXWBNXfTSr4o7Rcxd9l1EUOtsuzfuZATfmCgyWbqOlDAhfXSf8Zt4VwOInBGzzKn1ssAHHOx9P9Ahienw3fQhX2hiX7osm5UaavWF4tkJkr1VsB6OJ8/s400/Magic_Torus_Order-3_even_odd_number_pattern_P3.png" title="" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The "Loh-Shu" Magic Torus of Order-3 and its Even and Odd Number (x mod 2) Pattern P3</span></td></tr>
</tbody></table><div class="separator" style="clear: both; text-align: center;"></div><br />
<div style="text-align: justify;">The magic torus T3 of order-3 is shown here as seen from the <i>Scroll of Loh</i> magic square viewpoint.<br />
<br />
The even and odd number pattern P3 has reflection symmetry (with 6 lines of symmetry); rotational symmetry (of order 4); and point symmetry (over number 5, between numbers 3 and 7, between numbers 1 and 9, and between numbers 4, 6, 2, and 8).</div><div style="text-align: justify;"><br />
</div><h2 style="text-align: justify;">The Even and Odd Number Patterns of the Magic Tori of Order-4</h2><br />
<div style="text-align: justify;">Only consecutively numbered magic tori (<i>with numbers from 1 to n²</i>) are studied here, and therefore, for <i>order-4</i>, the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> <i>MC = 34</i>.</div><br />
<div style="text-align: justify;"><div style="text-align: justify;">The <a href="https://carresmagiques.blogspot.com/2012/10/table-of-fourth-order-magic-tori.html" rel="" target="_blank">"Table of Fourth-Order Magic Tori"</a> lists and describes each magic torus of order-4 using index numbers, while <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">"255 Fourth-Order Magic Tori, and 1 Third-Order Magic Torus"</a> gives a group categorisation of the magic tori of order-4 using type numbers. Both of these classifications give the details of the <a href="http://magic-squares.net/order4list.htm" rel="" target="_blank">Frénicle indexed magic squares</a> that are displayed by each torus.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">In the study that follows it can be seen that there are 4 essentially different even and odd number patterns on the magic tori of order-4:</div><h3 style="text-align: justify;"><br />
The Order-4 Even and Odd Number Pattern P4.1<br />
(represented by the pandiagonal torus T4.198)</h3><br />
</div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjskGxHnPnh26oCh9Lg1otLHKrdoMxqzDUFWq1WcHg3jIVsbTodIehmaWXAqr0Xbilt_yaBwzw7YoHPVQftE9Npcc6Gqv4YBR46tCalWX8Q8hQBcIm9JFPpB6lsBgdtSwZnFtqnhi3ez7Q/s1600/Pandiagonal_Torus_T4_198_Order-4_even_odd_number_pattern_P4_1.png" style="margin-left: auto; margin-right: auto;"><img alt="A pandiagonal torus or pandiagonal square of order-4 and its even and odd number pattern P4.1." border="0" data-original-height="768" data-original-width="1600" height="210" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjskGxHnPnh26oCh9Lg1otLHKrdoMxqzDUFWq1WcHg3jIVsbTodIehmaWXAqr0Xbilt_yaBwzw7YoHPVQftE9Npcc6Gqv4YBR46tCalWX8Q8hQBcIm9JFPpB6lsBgdtSwZnFtqnhi3ez7Q/s640/Pandiagonal_Torus_T4_198_Order-4_even_odd_number_pattern_P4_1.png" title="" width="442" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The Pandiagonal Torus T4.198 of Order-4 and its Even and Odd Number (x mod 2) Pattern P4.1</span></td></tr>
</tbody></table><div class="separator" style="clear: both; text-align: center;"></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The pandiagonal torus of order-4 (with <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" rel="" target="_blank">index n° T4.198</a> and <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">type n° T4.01.2</a>) is shown here as seen from the <a href="http://magic-squares.net/order4lista.htm#107" rel="" target="_blank">Frénicle n° 107</a> magic square viewpoint.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The even and odd number pattern P4.1 has reflection symmetry (with 6 lines of symmetry); rotational symmetry (of order 2); and multiple point symmetry when reading as a torus. The pattern P4.1 also has negative symmetry (evens to odds and vice versa).</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The even and odd number pattern P4.1 concerns 79 out of the 255 magic tori, and 404 out of the 880 magic squares of order-4. These include the 3 pandiagonal tori that display 48 pandiagonal squares; 30 semi-pandiagonal tori that display 240 semi-pandiagonal squares; 12 partially pandiagonal tori that display 48 partially pandiagonal squares; and also 34 basic magic tori that display 68 basic magic squares.</div><div style="text-align: justify;"><br />
</div><h3 style="text-align: justify;">The Order-4 Even and Odd Number Pattern P4.2<br />
(represented by the semi-pandiagonal torus T4.059)</h3><br />
<div class="separator" style="clear: both; text-align: center;"></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHY8yxvgcwhnWX5vc2j0fK2NezrGlO-H-Sn6RfDDOpMR5ywWJldwhKuug5QdvL1ddW_dHkg-kLRFr_fTLAyMVg0dfJkTc2bHthONO0jX2ZGt0vzB9G2FJhrZ5yqyTbgb_bweVtLq419Vo/s1600/Semi-Pandiagonal_Torus_T4_059_Order-4_even_odd_number_pattern_P4_2.png" style="margin-left: auto; margin-right: auto;"><img alt="A semi-pandiagonal torus or semi-pandiagonal square of order-4 and its even and odd number pattern P4.2." border="0" data-original-height="767" data-original-width="1600" height="210" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHY8yxvgcwhnWX5vc2j0fK2NezrGlO-H-Sn6RfDDOpMR5ywWJldwhKuug5QdvL1ddW_dHkg-kLRFr_fTLAyMVg0dfJkTc2bHthONO0jX2ZGt0vzB9G2FJhrZ5yqyTbgb_bweVtLq419Vo/s640/Semi-Pandiagonal_Torus_T4_059_Order-4_even_odd_number_pattern_P4_2.png" title="" width="442" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The Semi-Pandiagonal Torus T4.059 of Order-4 and its Even and Odd Number (x mod 2) Pattern P4.2</span></td></tr>
</tbody></table><div class="separator" style="clear: both; text-align: center;"></div><br />
<div style="text-align: justify;">The semi-pandiagonal torus of order-4 (with <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">index n° T4.059</a> and <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">type n° T4.02.2.01</a>) is shown here as seen from the <a href="http://magic-squares.net/order4lista.htm#021" rel="nofollow" target="_blank">Frénicle n° 21</a> magic square viewpoint.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The even and odd number pattern P4.2 has reflection symmetry (with 8 lines of symmetry); rotational symmetry (of order 4); and multiple point symmetry when reading as a torus. The pattern P4.2 also has negative symmetry (evens to odds and vice versa).</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The even and odd number pattern P4.2 concerns 72 out of the 255 magic tori, and 256 out of the 880 magic squares of order-4. These include 18 semi-pandiagonal tori that display 144 semi-pandiagonal squares; 6 partially pandiagonal tori that display 16 partially pandiagonal squares; and also 48 basic magic tori that display 96 basic magic squares.</div><div style="text-align: justify;"><br />
</div><h3 style="text-align: justify;">The Order-4 Even and Odd Number Pattern P4.3<br />
(represented by the partially pandiagonal torus T4.186)</h3><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh4-Qp54ZSnn6XUf5BAOlJW19e5Qz1A_apU0Ss1QsqTQTnqQlznxdqSGboXiNnOUdCaOArXhKwackUCbSxANBeDKpNWKWJr04QY14ephjdhBiSMn8NTElGJOOI35ypcf41ZAFRSAaLg2CA/s1600/Part_Pandiagonal_Torus_T4_186_Order-4_even_odd_number_pattern_P4_3.png" style="margin-left: auto; margin-right: auto;"><img alt="A partially pandiagonal torus or partially pandiagonal square of order-4 and its even and odd number pattern P4.3." border="0" data-original-height="766" data-original-width="1600" height="210" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh4-Qp54ZSnn6XUf5BAOlJW19e5Qz1A_apU0Ss1QsqTQTnqQlznxdqSGboXiNnOUdCaOArXhKwackUCbSxANBeDKpNWKWJr04QY14ephjdhBiSMn8NTElGJOOI35ypcf41ZAFRSAaLg2CA/s640/Part_Pandiagonal_Torus_T4_186_Order-4_even_odd_number_pattern_P4_3.png" title="" width="442" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The Partially Pandiagonal Torus T4.186 of Order-4 and its Even and Odd Number (x mod 2) Pattern P4.3</span></td></tr>
</tbody></table><div class="separator" style="clear: both; text-align: center;"></div><br />
<div style="text-align: justify;">The partially pandiagonal torus (with <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">index n° T4.186</a> and <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">type n° T4.03.1.3</a>) is shown here as seen from the <a href="http://magic-squares.net/order4lista.htm#100" rel="" target="_blank">Frénicle n° 100</a> magic square viewpoint.</div><br />
<div style="text-align: justify;">The even and odd number pattern P4.3 has reflection symmetry (with 8 lines of symmetry); rotational symmetry (of order 4); and multiple point symmetry when reading as a torus. The pattern P4.3 also has negative symmetry (evens to odds and vice versa).</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The even and odd number pattern P4.3 concerns 16 out of the 255 magic tori, and 44 out of the 880 magic squares of order-4. These include 6 partially pandiagonal tori that display 24 partially pandiagonal squares; and also 10 basic magic tori that display 20 basic magic squares.</div><div style="text-align: justify;"><br />
</div><h3 style="text-align: justify;">The Order-4 Even and Odd Number Pattern P4.4<br />
(represented by the basic magic torus T4.062)</h3><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgi5kEmyFL1sOwVY0CdjKF9RxgsMqZ1_xYtP28jrnj-MMb3Cwn0gxJU7a1UeBI3gk9c71H3d4Zlez1ayosyyR_jCdP5Bps4MTjtbe25nSWLWNAKa1e1Q6nNYNzqmvcMYHDYzQFeIa_O3fw/s1600/Basic_Magic_Torus_T4_062_Order-4_even_odd_number_pattern_P4_4.png" style="margin-left: auto; margin-right: auto;"><img alt="A basic magic torus or basic magic square of order-4 and its even and odd number pattern P4.4." border="0" data-original-height="765" data-original-width="1600" height="210" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgi5kEmyFL1sOwVY0CdjKF9RxgsMqZ1_xYtP28jrnj-MMb3Cwn0gxJU7a1UeBI3gk9c71H3d4Zlez1ayosyyR_jCdP5Bps4MTjtbe25nSWLWNAKa1e1Q6nNYNzqmvcMYHDYzQFeIa_O3fw/s640/Basic_Magic_Torus_T4_062_Order-4_even_odd_number_pattern_P4_4.png" title="" width="442" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The Basic Magic Torus T4.062 of Order-4 and its Even and Odd Number (x mod 2) Pattern P4.4</span></td></tr>
</tbody></table><br />
<div style="text-align: justify;">The basic magic torus (with <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" rel="" target="_blank">index n° T4.062</a> and <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">type n° T4.05.1.12</a>) is shown here as seen from the <a href="http://magic-squares.net/order4lista.htm#037" rel="" target="_blank">Frénicle n° 37</a> magic square viewpoint.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The even and odd number pattern P4.4 has reflection symmetry (with 8 lines of symmetry); rotational symmetry (of order 2); and multiple point symmetry when reading as a torus. The pattern P4.4 also has negative symmetry (evens to odds and vice versa).</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The even and odd number pattern P4.4 concerns 88 out of the 255 magic tori, and 176 out of the 880 magic squares of order-4. All of these 88 magic tori and the displayed 176 magic squares are basic magic.</div><div style="text-align: justify;"><br />
</div><h3 style="text-align: justify;">Observations on the Even and Odd Number Patterns of the Magic Tori and Magic Squares of Order-4</h3><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The findings of the even and odd number patterns of the magic tori of order-4 are recapitulated and analysed in comparative tables, (together with the <a href="http://djm.cc/library/Amusements_in_Mathematics_Dudeney_edited02.pdf#Page=128" rel="" target="_blank">Dudeney complementary number patterns</a> and the <a href="https://carresmagiques.blogspot.com/2017/09/self-complementary-magic-tori-order-4.html" target="_blank">Magic Torus</a><a href="https://carresmagiques.blogspot.com/2020/04/self-complementary-magic-tori-order-4.html" target="_blank"> self-complementary and paired complementary number patterns</a>), in the <a href="https://drive.google.com/file/d/1gBoMFsMa0p_c26HZDC4Eu0UutZDvkZuv/view?usp=sharing" rel="" target="_blank">file below:</a></div><br />
<iframe height="375px" src="https://docs.google.com/viewer?srcid=1gBoMFsMa0p_c26HZDC4Eu0UutZDvkZuv&pid=explorer&efh=false&a=v&chrome=false&embedded=true" width="518px"></iframe><br />
<br />
<h2 style="text-align: justify;">The Even and Odd Number Patterns of the Semi-Magic Tori of Order-4</h2><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Only consecutively numbered semi-magic tori (<i>with numbers from 1 to n²</i>) are studied here, and consequently, for the <i>order-4</i>, the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> <i>MC = 34</i>.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">In <a href="https://carresmagiques.blogspot.com/2012/01/255-fourth-order-magic-tori-and-1-third.html" target="_blank">"255 Fourth-Order Magic Tori, and 1 Third-Order Magic Torus"</a> the 4,038 semi-magic tori of order-4 have been sorted, and type numbers have been attributed taking into account the arrangements of their magic diagonals (if any).<i> </i></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Each of the four even and odd number patterns already found above on the magic tori of order-4, also occur on semi-magic tori of order-4. For example, from left to right below, we find a semi-magic torus type T4.08.0W with pattern P4.1; a semi-magic torus type T4.08.0X with pattern P4.2; a semi-magic torus type T4.07.0Y with pattern P4.3; and a semi-magic torus type T4.09.00Z with pattern P4.4:<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8aXYDQSmLlsAEjNbZ1vVtckYOsQxJVFzRBQcdJKYFQaZ-5-rAVgE6p4p72HHQAUFRg-jUivrujFKbD8bnZeEuneZIVY82UUhh7oh4ovRR1gCPQ7hE6WeiUR1atWmOOTHeVuKylV8B1bw/s1600/Semi-Magic_Tori_of_order-4_with_even_odd_number_patterns_P4_1_2_3_4.png" style="margin-left: auto; margin-right: auto;"><img alt="Semi-magic tori or semi-magic squares of order-4 that show the even and odd number patters P4.1 to P4.4." border="0" data-original-height="353" data-original-width="1600" height="86" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8aXYDQSmLlsAEjNbZ1vVtckYOsQxJVFzRBQcdJKYFQaZ-5-rAVgE6p4p72HHQAUFRg-jUivrujFKbD8bnZeEuneZIVY82UUhh7oh4ovRR1gCPQ7hE6WeiUR1atWmOOTHeVuKylV8B1bw/s640/Semi-Magic_Tori_of_order-4_with_even_odd_number_patterns_P4_1_2_3_4.png" title="" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Semi-Magic Tori of Order-4 with Even and Odd Number (x mod 2) Patterns P4.1, P4.2, P4.3 and P4.4</span></td></tr>
</tbody></table></div><br />
<div style="text-align: justify;">The even and odd number patterns P4.1 to P4.4 are not the only ones that can be found, but the patterns which are specific to the semi-magic tori of order-4 have neither been fully investigated nor precisely counted, and <i>the examples that follow only represent some of the different varieties.</i></div><div style="text-align: justify;"><br />
</div><h3 style="text-align: justify;">The Order-4 Even and Odd Number Pattern P4.5<br />
(represented by the semi-magic torus type T4.06.0A)</h3><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyrGFHOYXZ98QwVRQ6X1lPmmsh5Au9vsEtx0ELHBvLenWzKWwTJ_WKu8QBXxEljeTUDZzIazaEHwPoyAUgoaTaeWHeRFtPlSlH5crNsfwD0YEYX_WNkKs5VjY7RtBKWC0QvgabbvIlS_Q/s1600/Semi-Magic_Torus_T4_06_0A_Order-4_even_odd_number_pattern_P4_5.png" style="margin-left: auto; margin-right: auto;"><img alt="A semi-magic torus or semi-magic square of order-4 and its even and odd number pattern P4.5." border="0" data-original-height="766" data-original-width="1600" height="210" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyrGFHOYXZ98QwVRQ6X1lPmmsh5Au9vsEtx0ELHBvLenWzKWwTJ_WKu8QBXxEljeTUDZzIazaEHwPoyAUgoaTaeWHeRFtPlSlH5crNsfwD0YEYX_WNkKs5VjY7RtBKWC0QvgabbvIlS_Q/s640/Semi-Magic_Torus_T4_06_0A_Order-4_even_odd_number_pattern_P4_5.png" title="" width="442" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The Semi-Magic Torus type T4.06.0A of Order-4 and its Even and Odd Number (x mod 2) Pattern P4.5</span></td></tr>
</tbody></table><br />
This semi-magic torus type n° T4.06.0A was found by Walter Trump, and has been previously illustrated in <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">"255 Fourth-Order Magic Tori, and 1 Third-Order Magic Torus"</a>.<br />
<br />
The even and odd number pattern P4.5 has diagonal reflection symmetry (with 4 lines of symmetry); and negative (evens to odds and vice versa) rotational symmetry (of order 2). The blocks of even and odd numbers are translations of each other.<br />
<br />
<h3 style="text-align: justify;">The Order-4 Even and Odd Number Pattern P4.6<br />
(represented by the semi-magic torus type T4.07.0A)</h3><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiFzxo05eG2IsGHy0tpq9KXw9MnXsFHSZ6oKFcl0B7w_HFPo4RMsOx3_j4taQMEscxRKv4VlEvTIbSJ66rfQIOF9KX9c_xyBtl30KychUeTystrzA0knNPTbpOAnbmWaO3ngRT1DLc3hg/s1600/Semi-Magic_Torus_T4_07_0A_Order-4_even_odd_number_pattern_P4_6.png" style="margin-left: auto; margin-right: auto;"><img alt="A semi-magic torus or semi-magic square of order-4 and its even and odd number pattern P4.6." border="0" data-original-height="764" data-original-width="1600" height="210" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiFzxo05eG2IsGHy0tpq9KXw9MnXsFHSZ6oKFcl0B7w_HFPo4RMsOx3_j4taQMEscxRKv4VlEvTIbSJ66rfQIOF9KX9c_xyBtl30KychUeTystrzA0knNPTbpOAnbmWaO3ngRT1DLc3hg/s640/Semi-Magic_Torus_T4_07_0A_Order-4_even_odd_number_pattern_P4_6.png" title="" width="442" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The Semi-Magic Torus type T4.07.0A of Order-4 and its Even and Odd Number (x mod 2) Pattern P4.6</span></td></tr>
</tbody></table><br />
<div style="text-align: justify;">This semi-magic torus type n° T4.07.0A was found by Walter Trump, and has been previously illustrated in <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">"255 Fourth-Order Magic Tori, and 1 Third-Order Magic Torus"</a>.<br />
<br />
The even and odd number pattern P4.6 has reflection symmetry (with 4 lines of symmetry); rotational symmetry (of order 2); and multiple point symmetry when reading as a torus. The blocks of even and odd numbers are translations of each other.<br />
<br />
<h3 style="text-align: justify;">The Order-4 Even and Odd Number Pattern P4.7<br />
(represented by the semi-magic torus type T4.09.00M)</h3><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhaX8n6qqDNvKRbIh7iDa0rGI_N31gaW5uyeTlPIJ1DB9RGoJ-_mPIrPXRV85zt9jwltuK9iE7kMzZy6M27CvqhgPH3QGOKcAamr6J0Q4x42KNaqPBZbhKX1hiPIuT06WJUn_FskzyI2os/s1600/Semi-Magic_Torus_T4_09_00M_Order-4_even_odd_number_pattern_P4_7.png" style="margin-left: auto; margin-right: auto;"><img alt="A semi-magic torus or semi-magic square of order-4 and its even and odd number pattern P4.7." border="0" data-original-height="769" data-original-width="1600" height="210" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhaX8n6qqDNvKRbIh7iDa0rGI_N31gaW5uyeTlPIJ1DB9RGoJ-_mPIrPXRV85zt9jwltuK9iE7kMzZy6M27CvqhgPH3QGOKcAamr6J0Q4x42KNaqPBZbhKX1hiPIuT06WJUn_FskzyI2os/s640/Semi-Magic_Torus_T4_09_00M_Order-4_even_odd_number_pattern_P4_7.png" title="" width="442" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The Semi-Magic Torus type T4.09.00M of Order-4 and its Even and Odd Number (x mod 2) Pattern P4.7</span></td></tr>
</tbody></table><br />
<div style="text-align: justify;">This semi-magic torus type n° T4.09.00M was found by Walter Trump, and has been previously illustrated in <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">"255 Fourth-Order Magic Tori, and 1 Third-Order Magic Torus"</a>.<br />
<br />
The even and odd number pattern P4.7 has both positive and negative reflection symmetry; negative rotational symmetry (of order 2); and multiple negative point symmetry when reading as a torus. The blocks of even and odd numbers are translations of each other.<br />
<br />
<h3 style="text-align: justify;">The Order-4 Even and Odd Number Pattern P4.8<br />
(represented by the semi-magic torus type T4.10.000X)</h3><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh38jibiZe91W0GvY-OGNqwJiqF3q5zvV1HffOHz8NRSG05Hdyt_uMZVnrT8jUfV-pNnlf06veGmXoZgTA1GkeZ_L0XR1cmgrfnJV3NSKYq18uOQiRpPxGnOWGZGvPMBJv7p6M0jpyroPM/s1600/Semi-Magic_Torus_T4_10_000X_Order-4_even_odd_number_pattern_P4_8.png" style="margin-left: auto; margin-right: auto;"><img alt="A semi-magic torus or semi-magic square of order-4 and its even and odd number pattern P4.8." border="0" data-original-height="765" data-original-width="1600" height="210" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh38jibiZe91W0GvY-OGNqwJiqF3q5zvV1HffOHz8NRSG05Hdyt_uMZVnrT8jUfV-pNnlf06veGmXoZgTA1GkeZ_L0XR1cmgrfnJV3NSKYq18uOQiRpPxGnOWGZGvPMBJv7p6M0jpyroPM/s640/Semi-Magic_Torus_T4_10_000X_Order-4_even_odd_number_pattern_P4_8.png" title="" width="442" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The Semi-Magic Torus type T4.10.000X of Order-4 and its Even and Odd Number (x mod 2) Pattern P4.8</span></td></tr>
</tbody></table><br />
<span style="font-family: inherit;"><span style="font-family: inherit;">3,726 semi-magic tori of the type 10</span></span> have been found by Walter Trump, and his findings are detailed in <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">"255 Fourth-Order Magic Tori, and 1 Third-Order Magic Torus"</a>.<br />
<br />
<div style="text-align: justify;">The T4.10.000X's even and odd number pattern P4.8 has negative reflection symmetry (2 lines of symmetry); negative rotational symmetry (of order 2); and multiple point symmetry when reading as a torus. The blocks of even and odd numbers are translations of each other.<br />
<br />
<h2>General Observations</h2><br />
The <a href="https://carresmagiques.blogspot.com/2020/04/table-of-fourth-order-magic-tori.html" target="_blank">"Table of Fourth-Order Magic Tori"</a> has been revised to include the even and odd number pattern references for each of the magic tori of order-4 (listed together with the Frénicle indexed magic squares that each magic torus displays).</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Other interesting websites that examine, but do not enumerate, the different even and odd number patterns on magic squares of order-4, include <a href="http://www.cafe64.net/numbers/4x4/4x4.html" rel="nofollow" target="_blank">"4x4 Magic Squares"</a> by Dan Rhett and <a href="http://vipulchaskar.blogspot.com/2016/03/pattern-in-magic-squares.html" rel="nofollow" target="_blank">"Pattern in Magic Squares"</a> by Vipul Chaskar.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">A brief look at higher-orders suggests that the order-5 has many irregular patterns; the order-6 has many patterns with negative reflection symmetry (evens to odds and vice versa); the order-7 has many patterns with rotational symmetry; and the order-8 has patterns very like those of the order-4 examined above. All of these orders merit an in-depth analysis of their even and odd number patterns.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">In conclusion, it is interesting to note that <span style="font-size: small;"><span style="font-weight: normal;">the Arab mathematicians of the tenth century constructed odd-order magic squares with striking even and odd number patterns (as for example the magic squares in figures <i>b44</i> and <i>b49</i> on pages 243 and 248 of</span></span> <span style="font-size: small;"><span style="font-weight: normal;"><a href="https://books.google.fr/books?id=9CSKDgAAQBAJ&lpg=PP1&hl=fr&pg=PA243#v=onepage&q&f=true" rel="" target="_blank">Magic Squares in the Tenth Century: Two Arabic treatises by Anṭākī and Būzjānī</a>, translated by Jacques Sesiano). And in the same context, Paul Michelet has recently brought to my attention a</span></span><span style="font-size: small;"><span style="font-weight: normal;"><span style="font-size: small;"><span style="font-weight: normal;"><span style="font-size: small;"><span style="font-weight: normal;"> magnificent </span></span><span style="font-size: small;"><span style="font-weight: normal;"><span style="font-size: small;"><span style="font-weight: normal;">15 x 15 </span></span>magic square by</span></span></span></span></span></span><span style="font-size: small;"><span style="font-weight: normal;"> Ali b. Ahmad al</span></span><span style="font-size: small;"><span style="font-weight: normal;">-</span></span><span style="font-size: small;"><span style="font-weight: normal;"><span style="font-size: small;"><span style="font-weight: normal;">Anṭākī</span></span> (d. 987)</span></span><span style="font-size: small;"><span style="font-weight: normal;"><span style="font-size: small;"><span style="font-weight: normal;">. </span></span><a href="https://www.magischvierkant.com/two-dimensional-eng/15x15/al-antaakii/" rel="" target="_blank">Al-Anṭākī's bordered magic square</a> is solid </span></span><span style="font-size: small;"><span style="font-weight: normal;">evidence of the Middle Eastern mathematicians' </span></span><span style="font-size: small;"><span style="font-weight: normal;">mastery of even and odd number patterns!</span></span></div></div></div>
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<div class="separator" style="clear: both; text-align: center;">
<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-81557872905920544412019-08-13T17:05:00.008+02:002023-08-20T17:02:52.158+02:00Extra-Magic Tori and Knight Move Magic Diagonals<p style="text-align: justify;">
Published by <a href="https://www.primepuzzles.net/images/cr&ja.gif" rel="" target="_blank">Carlos Rivera</a> on his website <a href="https://primepuzzles.net/" rel="" target="_blank">"Prime Puzzles"</a> at the end of May 2019, the Puzzle 391 <a href="https://www.primepuzzles.net/puzzles/puzz_391.htm" rel="" target="_blank">"9 dots and 8 lines graph"</a> has stimulated a lot of conversation between magic square enthusiasts, and has inspired several ongoing experiments. It has also prompted me to look into the magic line graphs of <a href="https://carresmagiques.blogspot.com/2020/04/from-magic-square-to-magic-torus.html" target="_blank">magic tori</a>, and to search for cases having a maximum number of magic line intersections.</p>
<p style="text-align: justify;">
The extra-magic tori of orders 3 and 4 are here presented in detail, together with some further observations on the extra-magic tori of orders 5 to 8, the eighth-order being particularly significant for those who are interested in chess moves... </p>
<h3 style="text-align: justify;">The Definition of Extra-Magic</h3>
<p style="text-align: justify;">Extra-Magic can be defined as the presence of any magic line intersections on Magic Tori that are not usually taken into account in the study of Magic Squares.</p>
<p style="text-align: justify;">For example, the central intersection of the magic diagonals of a magic square takes place <i>between the number cells of even-order</i> magic squares, and <i>over a number cell of odd-order</i> magic squares. When we begin to study the wrap-around characteristics of the magic tori that display the magic squares, we notice that a same pair of magic diagonals produces two intersections on a magic torus. In even-orders the two intersections of a same pair of magic diagonals always produce two distinct magic squares on the magic torus. In odd-orders the two intersections of a same pair of magic diagonals only produce a single magic square, because the second intersection (at the opposite side of the torus), occurs between number cells, and cannot be at the centre of a second magic square.</p>
<p style="text-align: justify;">Therefore, in even-orders, the cases where the intersections of magic diagonals occur over number nodes (2 magic orthogonals + 2 magic diagonals), are often ignored, because these never produce magic squares. However, when looking at the limitless surface of a magic torus, <i>which has no centre</i>, a concentration of magic lines <i>that intersect over a number in even-orders</i> becomes a very interesting feature. </p>
<p style="text-align: justify;">A second example of extra-magic is the presence of knight move magic diagonals that occur on some magic tori (and on the magic squares that the magic tori display). The present study takes into account the eight traditional chess <a href="https://en.wikipedia.org/wiki/Knight_%28chess%29#Placement_and_movement" rel="" target="_blank">knight moves</a> of (2, 1), (1, 2), (-1, 2), (-2, 1), (-2, -1), (-1, -2), (1, -2) and (2, -1). Other <a href="https://en.wikipedia.org/wiki/Fairy_chess_piece#Leapers" rel="" target="_blank">fairy chess "leaper" move</a> magic diagonals also exist, such as the <a href="https://en.wikipedia.org/wiki/Camel_(chess)" rel="" target="_blank">Camel</a> (3, 1) and <a href="https://en.wikipedia.org/wiki/Zebra_(chess)" rel="" target="_blank">Zebra</a> (3, 2). However, in order to simplify the graphics of the magic line graphs, only traditional knight moves are considered here. It should be noted that knight move diagonals can never intersect at the centres of even-order magic squares, but they contribute to the weave of magic lines and are always an interesting feature when we observe the limitless surface of magic tori.</p>
<h3 style="text-align: justify;">Knight Move Magic Diagonals</h3>
<p style="text-align: justify;">Because knight move magic diagonals connect <i>n</i> numbers (where <i>n</i> is the order of the magic torus), and one of the knight's steps has a length of <i>2</i>, the diagonal has to make <i>2</i> loops round the magic torus. In lower-<i>n</i>-orders, the reduced number <i>n</i> of the necessary knight moves results in a proximity of the <i>2</i> loops, which in turn allows the knight to use <i>2 magic diagonal paths to connect a same series of numbers! </i>Please refer to <a href="https://drive.google.com/file/d/1gFx_JklpK_jKiLbgod142mR_ayXYXl1K/view?usp=sharing" rel="" target="_blank">"Knight Move Magic Diagonals on Magic Tori"</a> to see why knight move magic diagonals can sometimes have 2 paths for a same series of numbers.</p>
<h2 style="text-align: justify;">Extra-Magic Torus of Order-3<br />
with 4 Knight Move Magic Diagonals</h2>
<p style="text-align: justify;">
It came as quite a surprise to find that there are 4 knight move magic diagonals on the traditional Lo Shu magic square!</p>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7uekT7SY_obVyxKAYhAjKSNuP5iIk_bY-8ArEF0MXaLHC1wrZYja3bbEs6eDROn5Z704-WeaBo8jnbiy-nmhPx4SWs7NQlSeJR6hrdZZbeRtHWtB72MqbwwvEP4KGxIMOVcU7L4YSoig/s1600/Extra-Magic-Lo-Shu-Torus-of-Order-3_og.png" style="margin-left: auto; margin-right: auto;"><img alt="The Lo Shu extra-magic square of order-3 has 4 knight move magic diagonals." border="0" data-original-height="838" data-original-width="1600" height="208" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7uekT7SY_obVyxKAYhAjKSNuP5iIk_bY-8ArEF0MXaLHC1wrZYja3bbEs6eDROn5Z704-WeaBo8jnbiy-nmhPx4SWs7NQlSeJR6hrdZZbeRtHWtB72MqbwwvEP4KGxIMOVcU7L4YSoig/s400/Extra-Magic-Lo-Shu-Torus-of-Order-3_og.png" title="" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Lo-Shu Extra-Magic Torus T3 of Order-3</span></td></tr>
</tbody></table>
<p style="text-align: justify;">The extra<b>-</b>magic of the knight move diagonals produces multiple intersections of magic lines over the number 5. After the addition of the knight move magic lines that sum up to the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> <i>MC = 15</i>, the maximum number of magic lines at a nodal intersection is 8, (at number node 5). The total number of magic lines on the "Lo Shu" Magic Torus T3 is therefore 6 orthogonals (in red) + 2 classic diagonals (in red) + 4 knight move diagonals (in blue) = 12 magic lines.</p>
<p style="text-align: justify;">To the best of my knowledge, the knight move magic diagonals of the Lo Shu have not been mentioned in magic square literature before, but should I be mistaken, can you please advise me, and I will cite any previous authors accordingly. It should be noted that on page 37 of his 1877 paper <a href="https://books.google.ca/books?id=qxMLAAAAYAAJ&hl=fr&pg=PA37#v=onepage&q&f=false" rel="" target="_blank">"On the General Properties of Nasik Squares"</a>, <a href="https://en.wikisource.org/wiki/Author:Andrew_Hollingworth_Frost" rel="" target="_blank">Andrew Hollingworth Frost</a> describes (1, 2) "pathlets" of construction for a 3 x 3 square, <i>but his <span style="background-color: white;">diagram E is not the traditional Lo Shu. </span></i><br /></p>
<h3 style="text-align: justify;">Legend of the Extra-Magic Line Graphs</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhubFlfm0pvwxZTjJwmWrwkDoymbjwhkwfYrnCmPCwM77rjh8xMDEt7ibtYqkn65TKD2q87qU_S_X-uQXx_Hc1Q9mC6ENlJZaTQiCKzGv917Uhyphenhyphen-o3CMOGwJXsF_qhU6SYrVORC_dJ6y0Y/s1600/Extra-Magic-Torus-Legend.png" style="margin-left: auto; margin-right: auto;"><img alt="A legend of the magic line graphs of extra-magic tori and extra-magic squares." border="0" data-original-height="1205" data-original-width="1600" height="241" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhubFlfm0pvwxZTjJwmWrwkDoymbjwhkwfYrnCmPCwM77rjh8xMDEt7ibtYqkn65TKD2q87qU_S_X-uQXx_Hc1Q9mC6ENlJZaTQiCKzGv917Uhyphenhyphen-o3CMOGwJXsF_qhU6SYrVORC_dJ6y0Y/s320/Extra-Magic-Torus-Legend.png" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Legend of the Extra-Magic Line Graphs of Magic and Semi-Magic Tori</span></td></tr>
</tbody></table>
<h2 style="text-align: justify;">Extra-Magic Tori of Order-4 </h2>
<p style="text-align: justify;">More details of the Magic Tori of Order-4 <i>(and of the Frénicle indexed squares that these tori display)</i> can be found in <a href="https://carresmagiques.blogspot.com/2020/04/table-of-fourth-order-magic-tori.html" target="_blank">"The Table of Fourth-Order Magic Tori"</a> <i>(revised on the 20th June 2019 to include the details of the Extra-Magic Tori)</i>, and in <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">"255 Fourth-Order Magic Tori, and 1 Third-Order Magic Torus"</a>. </p>
<p style="text-align: justify;">The total numbers of Extra-Magic Tori (with extra-magic intersections and / or knight move magic diagonals), that were previously given at the end of the <a href="https://carresmagiques.blogspot.com/2020/04/table-of-fourth-order-magic-tori.html" target="_blank">"The Table of Fourth-Order Magic Tori"</a>, remain unchanged. Those concerning uniquely the knight move magic diagonals are now listed for more convenient reference in <a href="https://drive.google.com/file/d/1ofQfF2dtxxURLuZefz_zQItkJuMdAL2T/view?usp=sharing" rel="" target="_blank">"Knight Move Magic Diagonals in Magic Tori and Magic Squares of Order-4"</a>. Miguel Angel Amela has since confirmed my findings although we have a slightly different approach to the count of the double-slanting same-series knight move magic diagonals. For the sake of symmetry, and for comparison with higher-orders, I have chosen to count both of the same-series slants of knight move magic diagonals for the orders<i>-n</i> where <i>n < 6</i>.</p>
<p style="text-align: justify;">Only consecutively numbered magic tori (<i>with numbers from 1 to n²</i>) are studied here, and consequently, for <i>order-4</i>, the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> <i>MC = 34</i>.</p>
<h3 style="text-align: justify;">Extra-Magic Pandiagonal Torus T4.198 (type n° T4.01.2) of Order-4<br />
with 16 Extra-Magic Intersections</h3><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhf9HnwMm8a6y9sRijg-6iQfZkRvadQjQMBKmKAzbdM_IDxKTWU2PvCEaINotcGo1Fu_DuGhD7WUgLSJSi-reauYWk-wTDGi6S4m4xDiu18sObZ8U_eLw1qjzYFmxyNwTqMC71NC4H9IdE/s1600/Extra-Magic-Pandiagonal-Torus-T4_198-of-Order-4.png" style="margin-left: auto; margin-right: auto;"><img alt="The pandiagonal magic tori and magic squares of order-4 are extra-magic." border="0" data-original-height="1600" data-original-width="1592" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhf9HnwMm8a6y9sRijg-6iQfZkRvadQjQMBKmKAzbdM_IDxKTWU2PvCEaINotcGo1Fu_DuGhD7WUgLSJSi-reauYWk-wTDGi6S4m4xDiu18sObZ8U_eLw1qjzYFmxyNwTqMC71NC4H9IdE/s200/Extra-Magic-Pandiagonal-Torus-T4_198-of-Order-4.png" title="" width="197" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Pandiagonal Torus T4.198 of Order-4</span></td></tr>
</tbody></table>
<p style="text-align: justify;">Please note that here the torus viewpoint is deliberately centred on the number node 6. This is not a standard magic square presentation, but it means to show that on the limitless surface of the magic torus there is no fixed centre. The maximum number of magic lines at intersections (at each number node) is 4. The total number of magic lines on the order-4 pandiagonal <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">torus index n° T4.198</a> is 8 orthogonals (in red) + 8 classic diagonals (in red) = 16 magic lines.</p>
<p style="text-align: justify;">There are a total of 3 Pandiagonal <a href="https://carresmagiques.blogspot.com/2012/01/255-fourth-order-magic-tori-and-1-third.html#T4.01" target="_blank">Tori type T4.01</a> that each display 16 pandiagonal squares. The corresponding 48 pandiagonal squares are Dudeney type I.</p>
<h3 style="text-align: justify;">Extra-Magic Semi-Pandiagonal Torus T4.080 (type n° T4.02.3.02) of Order-4<br />
with 8 Knight Move Magic Diagonals</h3><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEim1BcdTGNv4mVHzVgc4Yz3RQwGnBnTO38FZ8hw1sqy5OBdxSkNgZYXGthl740CTVIsYIcffboQ2Ytmd-tyDXSjKWxsAir8YmLHqsf2lmxVcoM8ggveOveM-q2VBhNntAWqIAJq2Vm7ICE/s1600/Extra-Magic-S_Pandiagonal-Torus-T4_080-of-Order-4.png" style="margin-left: auto; margin-right: auto;"><img alt="The extra-magic semi-pandiagonal tori type T4.02.3 of order-4 have 8 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1600" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEim1BcdTGNv4mVHzVgc4Yz3RQwGnBnTO38FZ8hw1sqy5OBdxSkNgZYXGthl740CTVIsYIcffboQ2Ytmd-tyDXSjKWxsAir8YmLHqsf2lmxVcoM8ggveOveM-q2VBhNntAWqIAJq2Vm7ICE/s200/Extra-Magic-S_Pandiagonal-Torus-T4_080-of-Order-4.png" title="" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Semi-Pandiagonal Torus T4.080 of Order-4</span></td></tr>
</tbody></table>
<p style="text-align: justify;">The magic line graph of the semi-pandiagonal <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">torus index n° T4.080</a> (type n° T4.02.3.02) is here presented as seen from the magic square viewpoint Frénicle n° 33. After the addition of knight move magic diagonals (1, 10, 16, 7) + (1, 7, 16, 10) + (11, 4, 6, 13) + (13, 11, 4, 6) + (8, 15, 9, 2) + (8, 2, 9, 15) + (14, 5, 3, 12) + (14, 12, 3, 5) the maximum number of magic lines at a nodal intersection is 5 (at each number node). The total number of magic lines on the magic torus is 8 orthogonals (in red) + 4 classic diagonals (in red) + 8 knight move diagonals (in blue) = 20 magic lines.</p>
<p style="text-align: justify;">All of the 12 Semi-Pandiagonal <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html#T4.02.3.02" target="_blank">Tori Type T4.02.3</a> have 8 knight move magic diagonals, and each torus displays 8 semi-pandiagonal squares. The corresponding 96 semi-pandiagonal squares are Dudeney type V.</p>
<h3>Extra-Magic Partially Pandiagonal Torus T4.186 (type n° T4.03.1.3) of Order-4<br />
with 4 Extra-Magic Intersections and 4 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEheSuxqmdSKVEtmPHg_xaGEAN8F9pGhpC6-Dkv9OVfLB93G_uvhLjATc2FvIYuwCSD3pJ2GaaJbTNEYTQSioH1CqcRyGI2OCabJ3gHcgM6pw_TlCXHt8CtbFy0LCOUTlEEzf5m3zUdRq0Y/s1600/Extra-Magic-P_Pandiagonal-Torus-T4_186-of-Order-4.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic partially pandiagonal torus type T4.03.1 of order-4 has 4 knight move magic diagonals." border="0" data-original-height="1596" data-original-width="1600" height="199" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEheSuxqmdSKVEtmPHg_xaGEAN8F9pGhpC6-Dkv9OVfLB93G_uvhLjATc2FvIYuwCSD3pJ2GaaJbTNEYTQSioH1CqcRyGI2OCabJ3gHcgM6pw_TlCXHt8CtbFy0LCOUTlEEzf5m3zUdRq0Y/s200/Extra-Magic-P_Pandiagonal-Torus-T4_186-of-Order-4.png" title="" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Partially Pandiagonal Torus T4.186 of Order-4</span></td></tr>
</tbody></table>
<p style="text-align: justify;">The magic line graph of the partially pandiagonal <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">torus index n° T4.186</a> (type n° T4.03.1.3) is here presented as seen from the magic square viewpoint Frénicle n° 793. After the addition of the knight move magic diagonals (3, 12, 13, 6) + (3, 6, 13, 12) + (4, 5, 14, 11) + (4, 11, 14, 5), the maximum number of magic lines at a nodal intersection is 6 (at extra-magic number nodes 4, 5, 13, 12). The total number of magic lines on the magic torus is 8 orthogonals (in red) + 4 classic diagonals (in red) + 4 knight move diagonals (in blue) = 16 magic lines.</p>
<p style="text-align: justify;">2 out of the 6 Partially Pandiagonal <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">Tori Type T4.03.1</a> have similar knight move magic diagonals <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">(index n° T4.186 and T4.246)</a>, and both tori display 4 partially pandiagonal squares. The corresponding 8 partially pandiagonal squares are Dudeney Type VI.</p>
<h3 style="text-align: justify;">Extra-Magic Partially Pandiagonal Torus T4.060 (type n° T4.03.2.07) of Order-4<br />
with 4 Extra-Magic Intersections and 4 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjHfMMy-Uia04A3o_cfdnth3Er_yroJDpw3Mus90OXt9ashbDarRzuF1WfT_CydaKDvlM7XZuNF7oBTuF52kDoCRRTILr7E8VDwyrq4-9VU3DUlwPoPqrRfuegrFAYBY0s9VuRar-pJhy8/s1600/Extra-Magic-P_Pandiagonal-Torus-T4_060-of-Order-4.png" style="margin-left: auto; margin-right: auto;"><img alt="The extra-magic partially pandiagonal tori type T4.03.2 of order-4 have 4 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1593" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjHfMMy-Uia04A3o_cfdnth3Er_yroJDpw3Mus90OXt9ashbDarRzuF1WfT_CydaKDvlM7XZuNF7oBTuF52kDoCRRTILr7E8VDwyrq4-9VU3DUlwPoPqrRfuegrFAYBY0s9VuRar-pJhy8/s200/Extra-Magic-P_Pandiagonal-Torus-T4_060-of-Order-4.png" title="" width="198" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Partially Pandiagonal Torus T4.060 of Order-4</span></td></tr>
</tbody></table>
<p style="text-align: justify;">The magic line graph of the partially pandiagonal <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">torus index n° T4.060</a> (type n° T4.03.2.07) is here presented as seen from the magic square viewpoint Frénicle n° 472. After the addition of the knight move magic diagonals (1, 8, 14, 11) + (1, 11, 14, 8) + (5, 4, 10, 15) + (5, 15, 10, 4), the maximum number of magic lines at a nodal intersection is 6 (at extra-magic number nodes 4, 5, 11, 14). The total number of magic lines on the magic torus is 8 orthogonals (in red) + 4 classic diagonals (in red) + 4 knight move diagonals (in blue) = 16 magic lines.</p>
<p style="text-align: justify;">All of the 12 Partially Pandiagonal <a href="https://carresmagiques.blogspot.com/2012/01/255-fourth-order-magic-tori-and-1-third.html" target="_blank">Tori Type T4.03.2</a> have similar knight move magic diagonals, and each torus displays 4 partially pandiagonal squares. The corresponding 48 partially pandiagonal squares, which are evenly mixed on each torus, are either Dudeney type VII (24 squares), or Dudeney type IX (24 squares).</p>
<h3>Extra-Magic Partially Pandiagonal Torus T4.187 (type n° T4.03.3.2) of Order-4<br />
with 4 Extra-Magic Intersections and 4 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFNn31tMFAF550F-06MXlwme_yvalQpJz3tB3dmVeKue0nUrvgpNe4omjMZYBlKeOwUUMWmjufKyVRc2RcFpsaQmjS9f2ZMivpNDl4NrUZsbpymK7DecG-Tcuz_Eqg2CsRC3kRi1pgXsM/s1600/Extra-Magic-P_Pandiagonal-Torus-T4_187-of-Order-4.png" style="margin-left: auto; margin-right: auto;"><img alt="The extra-magic partially pandiagonal tori type T4.03.2 of order-4 have 4 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1598" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFNn31tMFAF550F-06MXlwme_yvalQpJz3tB3dmVeKue0nUrvgpNe4omjMZYBlKeOwUUMWmjufKyVRc2RcFpsaQmjS9f2ZMivpNDl4NrUZsbpymK7DecG-Tcuz_Eqg2CsRC3kRi1pgXsM/s200/Extra-Magic-P_Pandiagonal-Torus-T4_187-of-Order-4.png" title="" width="199" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Partially Pandiagonal Torus T4.187 of Order-4</span></td></tr>
</tbody></table>
<p style="text-align: justify;">The magic line graph of the partially pandiagonal <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">torus index n° T4.187</a> (type n° T4.03.3.2) is here presented as seen from the magic square viewpoint Frénicle n° 202. After the addition of the knight move magic diagonals (3, 4, 13, 14) + (3, 14, 13, 4) + (5, 6, 11, 12) + (5, 12, 11, 6) the maximum number of magic lines at a nodal intersection is 6 (at extra-magic number nodes 4, 5, 12, 13). The total number of magic lines on the magic torus is 8 orthogonals (in red) + 4 classic diagonals (in red) + 4 knight move diagonals (in blue) = 16 magic lines.</p>
<p style="text-align: justify;">Both of the Partially Pandiagonal <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">Tori Type T4.03.3</a> have similar knight move magic diagonals, and each torus displays 4 partially pandiagonal squares. The corresponding 8 partially pandiagonal squares are Dudeney type XI.</p>
<h3 style="text-align: justify;">Extra-Magic Partially Pandiagonal Torus T4.096 (type n° T4.04.1) of Order-4<br />
with 2 Extra-Magic Intersections</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEirMmSUR0GobHMwpuR3J9wDoMLtM-M3htFd0p19O1_yioelVd6iOeMtSaQ-msdw4EhTDC4HhMM6uaVULgCoH6S62eNEsWWvWrmXO_zN2zQKJeWVXX-OYJWv4GhuVbWCh_xhR7E1WdhJYeY/s1600/Extra-Magic-P_Pandiagonal-Torus-T4_096-of-Order-4.png" style="margin-left: auto; margin-right: auto;"><img alt="The extra-magic partially pandiagonal tori type T4.04 of order-4 have 2 extra-magic intersections." border="0" data-original-height="1600" data-original-width="1598" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEirMmSUR0GobHMwpuR3J9wDoMLtM-M3htFd0p19O1_yioelVd6iOeMtSaQ-msdw4EhTDC4HhMM6uaVULgCoH6S62eNEsWWvWrmXO_zN2zQKJeWVXX-OYJWv4GhuVbWCh_xhR7E1WdhJYeY/s200/Extra-Magic-P_Pandiagonal-Torus-T4_096-of-Order-4.png" title="" width="199" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Partially Pandiagonal Torus T4.096 of Order-4</span></td></tr>
</tbody></table>
<p style="text-align: justify;">The magic line graph of the partially pandiagonal <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">torus index n° T4.096</a> (type n° T4.04.1) is here presented as seen from the magic square viewpoint Frénicle n° 40. The maximum number of lines at intersections (over the extra-magic number nodes 1 and 13) is 4. The total number of magic lines on the magic torus is 8 orthogonals (in red) + 3 classic diagonals (in red) = 11 magic lines.</p>
<p style="text-align: justify;">The 4 Partially Pandiagonal <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">Tori Type T4.04</a> have 2 extra-magic intersections, and each of these tori displays 2 partially pandiagonal squares. The corresponding 8 partially pandiagonal squares, which are evenly mixed on each torus, are either Dudeney type VIII (4 squares) or Dudeney type X (4 squares). The tori type T4.04 were initially found thanks to Walter Trump's computing skills. </p>
<h3>Extra-Magic Basic Magic Torus T4.028 (type n° T4.05.1.78) of Order-4<br />
with 4 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEijRIbTWwi9-uyS8DahcmFienHzRJQygLAG0zA9ilYmV_Np27TTQYASkSTtCm6bhPwxf07qHzzH3C70HFl3sUpT_D4lDIja7eSbUePYZ7y8YUmsv5XQiCJPGBQR1vWJ72Hmj16RWHQ9w/s1600/Extra-Magic-Basic-Magic-Torus-T4_028-of-Order-4.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic basic magic torus type T4.05.1 of order-4 has 4 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1598" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEijRIbTWwi9-uyS8DahcmFienHzRJQygLAG0zA9ilYmV_Np27TTQYASkSTtCm6bhPwxf07qHzzH3C70HFl3sUpT_D4lDIja7eSbUePYZ7y8YUmsv5XQiCJPGBQR1vWJ72Hmj16RWHQ9w/s200/Extra-Magic-Basic-Magic-Torus-T4_028-of-Order-4.png" title="" width="199" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Basic Magic Torus T4.028 of Order-4</span></td></tr>
</tbody></table>
<p style="text-align: justify;">The magic line graph of the magic <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">torus index n° T4.028</a> (type N° T4.05.1.78) is here presented as seen from the magic square viewpoint Frénicle n° 502. After the addition of knight move magic diagonals (1, 5, 13, 15) + (1, 15, 13, 5) + (2, 4, 12, 16) + (2, 16, 12, 4) the maximum number of magic lines at a nodal intersection is 5 (at number nodes 4, 5, 12, 13). The total number of magic lines on the magic torus is 8 orthogonals (in red) + 2 classic diagonals (in red) + 4 knight move diagonals (in blue) = 14 magic lines.</p>
<p style="text-align: justify;">4 out of the 92 Basic Magic <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">Tori Type T4.05.1</a> have 4 knight move magic diagonals <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">(index n° T4.028, T4.102, T4.153 and T4.203)</a>, and each of these tori displays 2 basic magic squares. The corresponding 8 basic magic squares are Dudeney type VI.</p>
<h3 style="text-align: justify;">Extra-Magic Basic Magic Torus T4.071 (type n° T4.05.1.35) of Order-4<br />
with 8 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdlevG2WNklKr55CHYs1ZfuKkcoO6C7cSYsj6NqFTcnU-MmVsmS9zeoSlMvdx6JO0ifEZxiQnACTnqqWDjf7dbfwmXRiqgX2ItPNV7_nGaf-5rCu-VpkJwUmAA9Vo243gMfDL1dtYDWD0/s1600/Extra-Magic-Basic-Magic-Torus-T4_071-of-Order-4.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic basic magic torus type T4.05.1 of order-4 has 8 knight move magic diagonals." border="0" data-original-height="1598" data-original-width="1600" height="199" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdlevG2WNklKr55CHYs1ZfuKkcoO6C7cSYsj6NqFTcnU-MmVsmS9zeoSlMvdx6JO0ifEZxiQnACTnqqWDjf7dbfwmXRiqgX2ItPNV7_nGaf-5rCu-VpkJwUmAA9Vo243gMfDL1dtYDWD0/s200/Extra-Magic-Basic-Magic-Torus-T4_071-of-Order-4.png" title="" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Basic Magic Torus T4.071 of Order-4</span></td></tr>
</tbody></table>
<p style="text-align: justify;">The magic line graph of the magic <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">torus index n° T4.071</a> (type n° T4.05.1.35) is here presented as seen from the magic square viewpoint Frénicle n° 134. After the addition of knight move magic diagonals (1, 6, 15, 12) + (1, 12, 15, 6) + (2, 5, 16, 11) + (2, 11, 16, 5)+ (3, 8, 13, 10) + (3, 10, 13, 8) + (4, 7,14, 9) + (4, 9, 14, 7) the maximum number of magic lines at a nodal intersection is 5 (at number nodes 1, 4, 6, 8, 9, 11, 13, 16). The total number of magic lines on the magic torus is 8 orthogonals (in red) + 2 classic diagonals (in red) + 8 knight move diagonals (in blue) = 18 magic lines.</p>
<p style="text-align: justify;">6 out of the 92 Basic Magic <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">Tori Type T4.05.1</a> have 8 knight move magic diagonals <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">(index n° T4.071, T4.076, T4.134, T4.140, T4.227 and T4.232)</a>, and each of these tori displays 2 basic magic squares. The corresponding 12 basic magic squares are Dudeney type VI.</p>
<h3 style="text-align: justify;">Extra-Magic Basic Magic Torus T4.110 (type n° T4.05.2.29) of Order-4<br />
with 4 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjlTU5xh7TZbLJfqVLjqR5apHb2y88PfeyX-o93Z77EyACsfzJNPNTEMgjc2UP2Y6UryASG5gJ9p4J2ieOgB14d6HBIBiy9RFQclHsJbreNVDIgbjqtBBeqxCnxJ-LEkBeubQnb71SXJJ0/s1600/Extra-Magic-Basic-Magic-Torus-T4_110-of-Order-4.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic basic magic torus type T4.05.2 of order-4 has 4 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1598" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjlTU5xh7TZbLJfqVLjqR5apHb2y88PfeyX-o93Z77EyACsfzJNPNTEMgjc2UP2Y6UryASG5gJ9p4J2ieOgB14d6HBIBiy9RFQclHsJbreNVDIgbjqtBBeqxCnxJ-LEkBeubQnb71SXJJ0/s200/Extra-Magic-Basic-Magic-Torus-T4_110-of-Order-4.png" title="" width="199" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Basic Magic Torus T4.110 of Order-4</span></td></tr>
</tbody></table>
<p style="text-align: justify;">The magic line graph of the magic <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">torus index n° T4.110</a> (type n° T5.05.2.29) is here presented as seen from the magic square viewpoint Frénicle n° 568. After the addition of knight move magic diagonals (1, 9, 11, 13) + (1, 13, 11, 9) + (4, 6, 8, 16) + (4, 16, 8, 6) the maximum number of magic lines at a nodal intersection is 5 (at number nodes 6, 8, 11, 13). The total number of magic lines on the magic torus is 8 orthogonals (in red) + 2 classic diagonals (in red) + 4 knight move diagonals (in blue) = 14 magic lines.</p>
<p style="text-align: justify;">2 out of the 32 Basic Magic <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">Tori Type T4.05.2</a> have 4 knight move magic diagonals <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">(index n° T4.110 and T4.116)</a>, and both of these tori display 2 basic magic squares. The corresponding 4 basic magic squares, which are evenly mixed on each torus, are either Dudeney type VII (2 squares) or Dudeney type IX (2 squares).</p>
<h2 style="text-align: justify;">Extra-Magic Semi-Magic Tori of Order-4</h2>
<p style="text-align: justify;">More details of the Semi-Magic Tori of Order-4 can be found in <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">"255 Fourth-Order Magic Tori, and 1 Third-Order Magic Torus"</a>.</p>
<p style="text-align: justify;">Only consecutively numbered semi-magic tori (<i>with numbers from 1 to n²</i>) are studied here, and consequently, for the <i>order-4</i>, the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> <i>MC = 34</i>.</p>
<p style="text-align: justify;"><i>Extra-magic semi-magic tori of order-4 have neither been fully investigated nor precisely counted, and the examples shown below are a small selection of some of the different varieties.</i></p>
<h3 style="text-align: justify;">Extra-Magic Semi-Magic Torus Type n° T4.06.0A of Order-4<br />
with 8 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1Qqn3iOq4osAAItm4GpxrIAtQBG_cZTyi93qkEJLxD_Caq3ZZ6-cMFuiFCtNlZ71qnBDLuErPXztA2WtoaOcbJ8bKyoOM9mnMDah8lzoT4V3LGURiMQnkaYLkYEtwjNKTdEY1xAv6u2A/s1600/Extra-Magic-Semi-Magic-Torus-T4_06_0A-of-Order-4.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic semi-magic torus type T4.06.0A of order-4 has 8 knight move magic diagonals." border="0" data-original-height="1589" data-original-width="1600" height="198" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1Qqn3iOq4osAAItm4GpxrIAtQBG_cZTyi93qkEJLxD_Caq3ZZ6-cMFuiFCtNlZ71qnBDLuErPXztA2WtoaOcbJ8bKyoOM9mnMDah8lzoT4V3LGURiMQnkaYLkYEtwjNKTdEY1xAv6u2A/s200/Extra-Magic-Semi-Magic-Torus-T4_06_0A-of-Order-4.png" title="" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Semi-Magic Torus Type n° T4.06.0A of Order-4</span></td></tr>
</tbody></table>
<p style="text-align: justify;">The magic line graph of the <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html#Fourth-order_Semi-Magic_Tori" rel="" target="_blank">semi-magic torus type n° </a><a href="https://carresmagiques.blogspot.com/2012/01/255-fourth-order-magic-tori-and-1-third.html#Fourth-order_Semi-Magic_Tori" rel="nofollow" target="_blank">T4.06.0A</a> is based on a semi-magic torus that was first identified by Walter Trump. After the addition of knight move magic diagonals (1, 6, 16, 11) + (1, 11, 16, 6) + (2, 3, 15, 14) + (2, 14, 15, 3) + (4, 7, 13, 10) + (4, 10, 13, 7) + (5, 8, 12, 9) + (5, 9, 12, 8) the maximum number of magic lines at a nodal intersection is 5 (at all number nodes). The total number of magic lines on the semi-magic torus is 8 orthogonals (in red) + 4 classic diagonals (in red) + 8 knight move diagonals (in blue) = 20 magic lines.</p>
<h3 style="text-align: justify;">Extra-Magic Semi-Magic Torus Type n° T4.07.0A of Order-4<br />
with 4 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhpWsUOZWmFgAzNDvb9qUsGp_DuVbVOdvmPUMRHNKBrzuWrl0oHjAbtkSw41PpsczZatmPQvnrSKGdZLzFBQk7iv29kVzeay4E8n0Esi5i11qbZLXhgk-X7OPTD7pt95FpuMfEPHCTu1Eg/s1600/Extra-Magic-Semi-Magic-Torus-T4_07_0A-of-Order-4.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic semi-magic torus type T4.07.0A of order-4 has 4 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1600" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhpWsUOZWmFgAzNDvb9qUsGp_DuVbVOdvmPUMRHNKBrzuWrl0oHjAbtkSw41PpsczZatmPQvnrSKGdZLzFBQk7iv29kVzeay4E8n0Esi5i11qbZLXhgk-X7OPTD7pt95FpuMfEPHCTu1Eg/s200/Extra-Magic-Semi-Magic-Torus-T4_07_0A-of-Order-4.png" title="" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Semi-Magic Torus Type n° T4.07.0A of Order-4</span></td></tr>
</tbody></table>
<p style="text-align: justify;">The magic line graph of the <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html#Fourth-order_Semi-Magic_Tori" rel="" target="_blank">semi-magic torus type n° T4.07.0A</a> is based on a semi-magic torus that was first identified by Walter Trump. After the addition of knight move magic diagonals (1, 4, 13, 16) + (1, 16, 13, 4) + (2, 5, 12, 15) + (2, 15, 12, 5) the maximum number of magic lines at a nodal intersection is 5 (at number nodes 4, 5, 12, 13). The total number of magic lines on the semi-magic torus is 8 orthogonals (in red) + 2 classic diagonals (in red) + 4 knight move diagonals (in blue) = 14 magic lines.</p>
<h2>Extra-Magic Tori of Order-5</h2>
<p style="text-align: justify;">In the Order-5, studies of knight move magic diagonals have previously been made by <a href="http://www.multimagie.com/AmelaUHIMS.pdf" rel="" target="_blank">Miguel Angel Amela</a> in his paper <a href="https://drive.google.com/file/d/1Jr8OXTQbL1LewxZq5o0w4x-Nt7QpJoDo/view?usp=sharing" rel="" target="_blank">"Magic and Semi-Magic Squares of Order 5 - Rectangular Pandiagonality"</a> dated Spring 2011: Here he has identified 144 magic squares and 3456 semi-magic squares with "rectangular pandiagonality", and he has kindly authorised me to use one of these for an illustration of this extra-magic in a basic magic torus of the order-5.</p>
<p style="text-align: justify;">Only consecutively numbered magic tori (<i>with numbers from 1 to n²</i>) are studied here, and consequently for the <i>order-5</i>, the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> <i>MC = 65</i>.</p>
<p style="text-align: justify;"><i>Extra-magic tori of order-5 have neither been fully investigated nor precisely counted, and the examples shown below are a small selection of some of the different varieties.</i></p>
<h3>Extra-Magic Pandiagonal Torus Type T5.01<br />
with 6 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgaaqQaOoejJzkhro9KIRFCHTHLs2zjEJwKzqKghA9GoQTWMLuBviig00rcllqJYYAzZm73jvsNrGpebI8tNqXmZNyQKuHYV7D53ZyzYow-mQWm9BDSW5A8YDaMPFmla171p0Lwv9TeJmg/s1600/Extra-Magic-Pandiagonal-Torus-T5_01-of-Order-5.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic pandiagonal torus type T5.01 of order-5 has 6 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1572" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgaaqQaOoejJzkhro9KIRFCHTHLs2zjEJwKzqKghA9GoQTWMLuBviig00rcllqJYYAzZm73jvsNrGpebI8tNqXmZNyQKuHYV7D53ZyzYow-mQWm9BDSW5A8YDaMPFmla171p0Lwv9TeJmg/s200/Extra-Magic-Pandiagonal-Torus-T5_01-of-Order-5.png" title="" width="196" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Pandiagonal Torus Type T5.01 of Order-5</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph, based on a pandiagonal torus <a href="https://carresmagiques.blogspot.com/2020/04/251449712-fifth-order-magic-tori.html" target="_blank">type T5.01 of order-5</a>, attributed to <a href="https://fr.wikipedia.org/wiki/Philippe_de_La_Hire" rel="" target="_blank">Philippe de la Hire</a> (c. 1705) by <a href="https://en.wikipedia.org/wiki/Percy_Alexander_MacMahon" rel="" target="_blank">Percy Alexander MacMahon</a> in his 1902 paper <a href="https://www.nature.com/articles/065447a0.pdf" rel="" target="_blank">"Magic Squares and Other Problems upon a Chess Board"</a>, shows the presence of extra-magic with 6 knight move magic diagonals. After taking these into account, the maximum number of magic lines at a nodal intersection is 8 (at number nodes 12 and 13). The total number of magic lines on the pandiagonal torus is 10 orthogonals (in red) + 10 classic diagonals (in red) + 6 knight move diagonals (in blue) = 26 magic lines.</p>
<h3 style="text-align: justify;">Extra-Magic Partially Pandiagonal Torus Type n° T5.03.00A of Order-5<br />
with 2 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiOBjJkt53apZSx26wDw-cfbEb04WU83Co9MzPOMKoCj7_au2E7FJuWj2iYMDUAsTi6KjFN-f96pvTHy0ZQcbblPgQDMGSJksZvKoFOY8tNc7OXeoWzKyhFfVwLzqXCi3oNS_lOFwYLxuM/s1600/Extra-Magic-P_Pandiagonal-Torus-T5_03-of-Order-5.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic partially pandiagonal torus type T5.03 of order-5 has 2 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1561" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiOBjJkt53apZSx26wDw-cfbEb04WU83Co9MzPOMKoCj7_au2E7FJuWj2iYMDUAsTi6KjFN-f96pvTHy0ZQcbblPgQDMGSJksZvKoFOY8tNc7OXeoWzKyhFfVwLzqXCi3oNS_lOFwYLxuM/s200/Extra-Magic-P_Pandiagonal-Torus-T5_03-of-Order-5.png" title="" width="195" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Partially Pandiagonal Torus Type T5.03 of Order-5</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph, based on a partially pandiagonal torus <a href="https://carresmagiques.blogspot.com/2020/04/251449712-fifth-order-magic-tori.html" target="_blank">type n° T5.03.00A of order-5</a> found by <a href="http://www.trump.de/magic-squares/" rel="" target="_blank">Walter Trump</a> in 2012, shows the presence of extra-magic with 2 knight move magic diagonals. After the addition of the knight move diagonals (5, 9, 17, 21, 13) and (5, 17, 13, 9, 21), the maximum number of magic lines at a nodal intersection is 6 (at number nodes 5 and 21). The total number of magic lines on the partially pandiagonal torus is 10 orthogonals (in red) + 7 classic diagonals (in red) + 2 knight move diagonals (in blue) = 19 magic lines.</p>
<h3 style="text-align: justify;">Extra-Magic Partially Pandiagonal Torus Type n° T5.04.000A of Order-5<br />
with 2 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAXhj0nFA1zYhRA9tLsN-YVUDBcneNE_JAh1xQIt3HgRroznBappPh3esC42qDr3NOKJHlPu0cHzVfIA0D7wG0oJlV8PufMSCzd-qJ3oqdMlr4zu3WADoGzbj_BIuifgpN0bcCtTshAag/s1600/Extra-Magic-P_Pandiagonal-Torus-T5_04-of-Order-5.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic partially pandiagonal torus type T5.04 of order-5 has 2 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1561" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAXhj0nFA1zYhRA9tLsN-YVUDBcneNE_JAh1xQIt3HgRroznBappPh3esC42qDr3NOKJHlPu0cHzVfIA0D7wG0oJlV8PufMSCzd-qJ3oqdMlr4zu3WADoGzbj_BIuifgpN0bcCtTshAag/s200/Extra-Magic-P_Pandiagonal-Torus-T5_04-of-Order-5.png" title="" width="195" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Partially Pandiagonal Torus Type T5.04 of Order-5</span> </td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph, based on a partially pandiagonal torus <a href="https://carresmagiques.blogspot.com/2020/04/251449712-fifth-order-magic-tori.html" target="_blank">type n° T5.04.000A of order-5</a> found by <a href="http://www.trump.de/magic-squares/" rel="" target="_blank">Walter Trump</a> in 2012, shows the presence of extra-magic with 2 knight move magic diagonals. After the addition of the knight move diagonals (6, 9, 15, 11, 24) and (6, 11, 9, 24, 15), the maximum number of magic lines at a nodal intersection is 6 (at number nodes 11 and 15). The total number of magic lines on the partially pandiagonal torus is 10 orthogonals (in red) + 6 classic diagonals (in red) + 2 knight move diagonals (in blue) = 18 magic lines.</p>
<h3 style="text-align: justify;">Extra-Magic "Knight's Tour" Partially Pandiagonal Torus Type T5.06 of Order-5<br />
with 12 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi48SWVqG0tk6WuQuRAAaun-SK2kaA4NguGJAGmYAizpzq2aQOlBzASRECJ27_hs7WaYGb8Fi7nQ8nBaN-1uPVIOf1NVk2Msa9Yed2wyOdw14LDPwwfv655t3v0R-0Ztw-S-yv2dHxl-yo/s1600/Extra-Magic-P_Pandiagonal-Torus-T5_06-of-Order-5.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic "knight's Tour" partially pandiagonal torus type T5.06 of order-5 has 12 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1572" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi48SWVqG0tk6WuQuRAAaun-SK2kaA4NguGJAGmYAizpzq2aQOlBzASRECJ27_hs7WaYGb8Fi7nQ8nBaN-1uPVIOf1NVk2Msa9Yed2wyOdw14LDPwwfv655t3v0R-0Ztw-S-yv2dHxl-yo/s200/Extra-Magic-P_Pandiagonal-Torus-T5_06-of-Order-5.png" title="" width="196" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic "Knight's Tour" Partially Pandiagonal Torus Type T5.06 of Order-5</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph, based on a <a href="https://www.mayhematics.com/t/2t.htm#Five-Square_Magic_Torus_Tours" rel="" target="_blank">"knight's tour"</a> partially pandiagonal torus <a href="https://carresmagiques.blogspot.com/2020/04/251449712-fifth-order-magic-tori.html" target="_blank">type T5.06 of order-5</a>, published by <a href="https://en.wikipedia.org/wiki/William_Symes_Andrews" rel="" target="_blank">William Symes Andrews</a> in his book <a href="https://archive.org/details/magicsquarescube00andrrich/page/10" rel="" target="_blank">"Magic Squares and Cubes"</a> in 1908 (figure 20), shows the presence of extra-magic with 12 knight move magic diagonals. After the addition of the knight move magic diagonals, the maximum number of magic lines at a nodal intersection is 8 (at number node 13). The total number of magic lines on the partially pandiagonal torus is 10 orthogonals (in red) + 6 classic diagonals (in red) + 12 knight move diagonals (in blue) = 28 magic lines.</p>
<h3 style="text-align: justify;">Extra-Magic Basic Magic Torus Type T5.10 of Order-5<br />
with 20 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFrlBs-AGWtbtOH_o3Ol-zTlCHrpugS1Yj59V5D3Tzk2Ev49YvU2x99zyjGW5rpvXuoZOLUJ4LWoXfeOuXda2VNF4AbfUvWddNufKfcTLEWRjTl6dbS61S9bOoka7J2DYrY8XNLe9nS6U/s1600/Extra-Magic-Basic-Magic-Torus-T5_10-of-Order-5.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic basic magic torus type T5.10 of order-5 is knight move pandiagonal." border="0" data-original-height="1600" data-original-width="1568" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFrlBs-AGWtbtOH_o3Ol-zTlCHrpugS1Yj59V5D3Tzk2Ev49YvU2x99zyjGW5rpvXuoZOLUJ4LWoXfeOuXda2VNF4AbfUvWddNufKfcTLEWRjTl6dbS61S9bOoka7J2DYrY8XNLe9nS6U/s200/Extra-Magic-Basic-Magic-Torus-T5_10-of-Order-5.png" title="" width="195" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Basic Magic Torus Type T5.10 of Order-5</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph, based on a basic magic torus <a href="https://carresmagiques.blogspot.com/2020/04/251449712-fifth-order-magic-tori.html" target="_blank">type T5.10 of order-5</a> published by <a href="http://www.multimagie.com/AmelaUHIMS.pdf" rel="" target="_blank">Miguel Angel Amela</a> in his paper <a href="https://drive.google.com/file/d/1Jr8OXTQbL1LewxZq5o0w4x-Nt7QpJoDo/view?usp=sharing" rel="" target="_blank">"Magic and Semi-Magic Squares of Order 5 - Rectangular Pandiagonality"</a> in spring 2011, shows the presence of extra-magic with knight move pandiagonality. After the addition of the knight move magic diagonals, the maximum number of magic lines at a nodal intersection is 8 (at number node 13). The total number of magic lines on the magic torus is 10 orthogonals (in red) + 2 classic diagonals (in red) + 20 knight move diagonals (in blue) = 32 magic lines.</p>
<p style="text-align: justify;"><i>In order-5, Miguel Angel Amela has found a total of 144 Magic Tori with "Rectangular Pandiagonality". Each of these displays 1 magic square and 24 semi-magic squares, and the corresponding grand totals are therefore 144 magic squares and 3456 semi-magic squares with knight move pandiagonality!</i></p>
<h2 style="text-align: justify;">Extra-Magic Semi-Magic Torus of Order-5</h2><br />
<i>Extra-magic semi-magic tori of order-5 have neither been fully investigated nor precisely counted, and the example shown below is randomly chosen.</i>
<br /><br />
<h3 style="text-align: justify;">Extra-Magic Semi-Magic Torus Type n° T5.14000000000X of Order-5<br />
with 4 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhT-99XeFEkzo38YPMuZIKR6IpuFL9O1NweHoSYbV3KBPqsaF1frCARCrZpVz7Jlz2vfNDqfMwVh1pZufGavepfHSSLM2-pUY5bk2bEIzwFg9NLnzG3OIManZuELtjcrem_zd9HoNHiCuw/s1600/Extra-Magic-Semi-Magic-Torus-T5_14-of-Order-5.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic semi-magic torus type T5.14 of order-5 has 4 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1564" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhT-99XeFEkzo38YPMuZIKR6IpuFL9O1NweHoSYbV3KBPqsaF1frCARCrZpVz7Jlz2vfNDqfMwVh1pZufGavepfHSSLM2-pUY5bk2bEIzwFg9NLnzG3OIManZuELtjcrem_zd9HoNHiCuw/s200/Extra-Magic-Semi-Magic-Torus-T5_14-of-Order-5.png" title="" width="195" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Semi-Magic Torus Type T5.14 of Order-5</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph of a semi-magic torus <a href="https://carresmagiques.blogspot.com/2020/04/251449712-fifth-order-magic-tori.html" target="_blank">type n° T5.14.000000000X of order-5</a>, shows the presence of extra-magic with 4 knight move magic diagonals. After the addition of the knight move magic diagonals (2, 12, 19, 22, 10), (2, 22, 12, 10, 19), (5, 8, 12, 24, 16) and (5, 24, 8, 16, 12), the maximum number of magic lines at a nodal intersection is 7 (at number node 12). The total number of magic lines on the semi-magic torus is 10 orthogonals (in red) + 1 classic diagonal (in red) + 4 knight move diagonals (in blue) = 15 magic lines.</p>
<h2 style="text-align: justify;">Extra-Magic Tori of Order-6</h2>
<p style="text-align: justify;">In the Order-6, studies of knight move magic diagonals have previously been made by <a href="http://www.multimagie.com/AmelaUHIMS.pdf" rel="" target="_blank">Miguel Angel Amela</a> in his paper <a href="https://drive.google.com/file/d/1OWkPeS_9wOud9EdWGzrAfEabuFxdaDKr/view?usp=sharing" rel="" target="_blank">"Compact Magic and Semi-Magic Squares of Order n = 4k+2 - Rectangular Pandiagonality"</a> dated Spring 2011, and Miguel has kindly authorised me to use one of his squares for an illustration of this extra-magic in a compact semi-magic torus of order-6.</p>
<p style="text-align: justify;">Only consecutively numbered magic tori (<i>with numbers from 1 to n²</i>) are studied here, and consequently, for the <i>order-6</i>, the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> <i>MC = 111</i>.</p>
<p style="text-align: justify;"><i>Extra-magic tori of order-6 have neither been fully investigated nor precisely counted, and the examples shown below are selected samples of some of the different varieties.</i></p>
<h3 style="text-align: justify;">Extra-Magic Partially Pandiagonal Torus of Order-6<br />
with 6 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiR4XC5YTBfUojtJ7XkbVPcASmG6vVjUSgvsE2V96yDh51EX4utKbr55bDdYdT98xVU-z2jXjb__yNZY4J1SpKplvP1lP1_0idwbkiNXwXnWzYCYWQ5O5hOtvPi_ZvDVQQxh8c-AfctzPY/s1600/Extra-Magic-P_Pandiagonal-Torus-6KM-diag-Order-6.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic partially pandiagonal torus of order-6 has 6 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1600" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiR4XC5YTBfUojtJ7XkbVPcASmG6vVjUSgvsE2V96yDh51EX4utKbr55bDdYdT98xVU-z2jXjb__yNZY4J1SpKplvP1lP1_0idwbkiNXwXnWzYCYWQ5O5hOtvPi_ZvDVQQxh8c-AfctzPY/s200/Extra-Magic-P_Pandiagonal-Torus-6KM-diag-Order-6.png" title="" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Partially Pandiagonal Torus of Order 6 with 6 KM Magic Diagonals</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph, based on a partially pandiagonal torus of order-6 which <a href="https://budshaw.ca/KnightMove6.html" rel="" target="_blank">Harry White</a> has kindly authorised me to use, shows the presence of extra-magic with 6 knight move magic diagonals. After the addition of the knight move magic diagonals, the maximum number of magic lines at a nodal intersection is 5 (at number nodes 19, 20, 22). The total number of magic lines on the partially pandiagonal torus is 12 orthogonals (in red) + 3 classic diagonals (in red) + 6 knight move diagonals (in blue) = 21 magic lines.</p>
<h3 style="text-align: justify;">Extra-Magic Partially Pandiagonal torus of Order-6<br />
with 16 Extra-Magic Intersections and 4 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjfFLrAHuGb5e9gBankgorPZUHm56EO7IWqRltqzMVE81-XqNMZ2OalJzKvYy_nd9QqR-v4PtDvTnAYL1X0t_n6M4vcDWMCnfuB4AhtDXn7D9QA3xvErtDN8c0yZWwUsgesKDmCAibNMsk/s1600/Extra-Magic-P_Pandiagonal-Torus-4KM-diag-Order-6.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic partially pandiagonal torus of order-6 has 16 extra-magic intersections and 4 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1598" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjfFLrAHuGb5e9gBankgorPZUHm56EO7IWqRltqzMVE81-XqNMZ2OalJzKvYy_nd9QqR-v4PtDvTnAYL1X0t_n6M4vcDWMCnfuB4AhtDXn7D9QA3xvErtDN8c0yZWwUsgesKDmCAibNMsk/s200/Extra-Magic-P_Pandiagonal-Torus-4KM-diag-Order-6.png" title="" width="199" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Partially Pandiagonal Torus of Order-6 with 4 KM Magic Diagonals</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph, based on a partially pandiagonal torus of order-6 which <a href="https://www.gaspalou.fr/magic-squares/index.htm" rel="" target="_blank">Francis Gaspalou</a> has kindly authorised me to use, shows the presence of both extra-magic intersections and knight move magic diagonals. After the addition of the knight move magic diagonals, the maximum number of magic lines at a nodal intersection is 6 (at number nodes 7, 11, 26, 30). The total number of magic lines on the partially pandiagonal torus is 12 orthogonals (in red) + 8 classic diagonals (in red) + 4 knight move diagonals (in blue) = 24 magic lines.</p>
<h3 style="text-align: justify;">Extra-Magic Basic Magic Torus of Order-6<br />
with 2 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVTSdaPMFnKb1G-Xl6f46XLLh70QExdakF1Y_sq4hlMNmgEW6XAuu-9zPQFFn8rUdGUFWOqqI4f0XZ5Eef8RNop5BKa4cAZlxStS0W1eayRNJjle4IM973OtIvQVGFMZJXxRyuGrzcxOo/s1600/Extra-Magic-Basic-Magic-Torus-2KM-diag-Order-6.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic basic magic torus of order-6 has 2 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1600" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVTSdaPMFnKb1G-Xl6f46XLLh70QExdakF1Y_sq4hlMNmgEW6XAuu-9zPQFFn8rUdGUFWOqqI4f0XZ5Eef8RNop5BKa4cAZlxStS0W1eayRNJjle4IM973OtIvQVGFMZJXxRyuGrzcxOo/s200/Extra-Magic-Basic-Magic-Torus-2KM-diag-Order-6.png" title="" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Basic Magic Torus of Order-6 with 2 KM Magic Diagonals</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph, based on a basic magic torus of order-6 by <a href="https://en.wikipedia.org/wiki/William_Symes_Andrews" rel="" target="_blank">William Symes Andrews</a> in figure 311 of the 1917 re-edition of his book <a href="https://archive.org/details/magicsquarescube00andrrich/page/190" rel="" target="_blank">"Magic Squares and Cubes"</a>, shows the presence of extra-magic with 2 knight move magic diagonals. After the addition of the knight move magic diagonals, the maximum number of magic lines at a nodal intersection is 4 (at number nodes 5, 14, 23, 32). The total number of magic lines on the basic magic torus is 12 orthogonals (in red) + 2 classic diagonals (in red) + 2 knight move diagonals (in blue) = 16 magic lines.</p>
<h2 style="text-align: justify;">Extra-Magic Semi-Magic Tori of Order-6</h2>
<p style="text-align: justify;"><i>Extra-magic semi-magic tori of order-6 have neither been fully investigated nor precisely counted, and the examples shown below are selected samples of some of the different varieties.</i></p>
<h3 style="text-align: justify;">Extra-Magic Semi-Magic Torus of Order 6<br />
with 2 Extra-Magic Intersections and 1 Knight Move Magic Diagonal</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWmrAFLXGgFUp_iFK92bQINrVGiV5UBkZFDyrrX76xN1G305aPvTX5jb0AY2ltlUQWUcDKEMo2utHLSy5QzPFQcadlybe0sbxK1BLc2X_uh8hQveKu7JrJLxweYjAS75q66DmMBTXPUpQ/s1600/Extra-Magic-Semi-Magic-Torus-1KM-diag-Order-6.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic semi-magic torus of order-6 has 2 extra-magic intersections and a knight move magic diagonal." border="0" data-original-height="1600" data-original-width="1577" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWmrAFLXGgFUp_iFK92bQINrVGiV5UBkZFDyrrX76xN1G305aPvTX5jb0AY2ltlUQWUcDKEMo2utHLSy5QzPFQcadlybe0sbxK1BLc2X_uh8hQveKu7JrJLxweYjAS75q66DmMBTXPUpQ/s200/Extra-Magic-Semi-Magic-Torus-1KM-diag-Order-6.png" title="" width="196" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Semi-Magic Torus of Order-6 with 1 KM Magic Diagonal</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph, based on a semi-magic torus of order-6 previously found by <a href="http://www.trump.de/magic-squares/" rel="" target="_blank">Walter Trump</a> and already illustrated in <a href="https://carresmagiques.blogspot.com/2020/04/sixth-and-higher-order-magic-tori.html" target="_blank">"Sixth and Higher-Order Magic Tori"</a>, shows not only the presence of 2 extra-magic intersections, but also a single knight move magic diagonal. (The latter was not noticed at the time of the first illustration). Please note that here the torus viewpoint is deliberately centred on the number node 27. This is not a standard magic square presentation, but it means to show that on the limitless surface of the magic torus there is no fixed centre. After the addition of the knight move magic diagonal, the maximum number of magic lines at intersections (number nodes 3, 27, 28) is 4. The total number of magic lines on the semi-magic torus is 12 orthogonals (in red) + 2 classic diagonals (in red) + 1 knight move diagonal (in blue) = 15 magic lines.</p>
<h3 style="text-align: justify;">Extra-Magic Compact Semi-Magic Torus of Order-6<br />
with 24 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgoUhfBFTIZ4P1ISiYHUn927J0qwVCk8dlZY08vTJatkGzJ1zZbTv7UpnkxuzDUNHWb_UDsoE9V-AMHYGt3omKq-2QTI_0jomn0OccqJkmvxN1H9JP__AzxI9ajY-tbbNcugbHOqygU8cA/s1600/Extra-Magic-Semi-Magic-Torus-24KM-diag-Order-6.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic compact semi-magic torus of order-6 is knight move pandiagonal." border="0" data-original-height="1600" data-original-width="1598" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgoUhfBFTIZ4P1ISiYHUn927J0qwVCk8dlZY08vTJatkGzJ1zZbTv7UpnkxuzDUNHWb_UDsoE9V-AMHYGt3omKq-2QTI_0jomn0OccqJkmvxN1H9JP__AzxI9ajY-tbbNcugbHOqygU8cA/s200/Extra-Magic-Semi-Magic-Torus-24KM-diag-Order-6.png" title="" width="199" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Compact Semi-Magic Torus of Order-6 with 24 KM Magic Diagonals</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph is based on a compact semi-magic torus of order-6 with knight move pandiagonality, found by <a href="https://budshaw.ca/documents/No%20MFS%208k+4.pdf" rel="" target="_blank">Miguel Angel Amela</a> and published in his 2011 paper <a href="https://drive.google.com/file/d/1OWkPeS_9wOud9EdWGzrAfEabuFxdaDKr/view?usp=sharing" rel="" target="_blank">"Compact Magic and Semi-Magic Squares of Order n = 4k+2 - Rectangular Pandiagonality"</a>. After the addition of the knight move magic diagonals, the maximum number of magic lines at a nodal intersection is 6 (at all number nodes). The total number of magic lines on the semi-magic magic torus is 12 orthogonals (in red) + 0 classic diagonals (in red) + 24 knight move diagonals (in blue) = 36 magic lines.</p>
<p style="text-align: justify;">In a compact magic square, the sum of each <i>2 x 2</i> subsquare is equal to <i>4/n</i> of the magic constant <i>(MC)</i>, and for the order-<i>6</i> the sum of each of the <i>2 x 2</i> subsquares is therefore equal to <i>4/6 x 111 = 74</i>. Miguel Amela proves that, regardless of whether they are magic or semi-magic, all compact squares of orders <i>n = 4k+2</i> are also knight move pandiagonal. <i>Taking into account squares with consecutive numbers from 1 to n², he has calculated that there are 53136 compact (and therefore knight move pandiagonal) semi-magic squares of order-6. This implies that there are 1476 compact semi-magic tori with these characteristics in order-6.</i></p>
<h2>Extra-Magic Tori of Order-7 </h2>
<p style="text-align: justify;">In the Order-7, studies of knight move magic diagonals have previously been made by <a href="http://www.multimagie.com/AmelaUHIMS.pdf" rel="" target="_blank">Miguel Angel Amela</a> and he has kindly authorised me to use one of his basic magic squares for an illustration of knight move pandiagonality.</p>
<p style="text-align: justify;">Only consecutively numbered magic tori (<i>with numbers from 1 to n²</i>) are studied here, and consequently, for the <i>order-7</i>, the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> <i>MC = 175</i>.</p>
<p style="text-align: justify;"><br />
<i>Extra-magic tori of order-7 have neither been fully investigated nor precisely counted, and the examples shown below are selected samples of some of the different varieties.</i></p>
<h3>Extra-Magic "Knight's Tour" Pandiagonal Torus of Order-7<br />
with 16 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg8PNyaqYdk3e9meqBbTs1U0Ghyf2XBjqLqWKwOKNFSCgZZ8wi7kctPrj7YVPFHrl-2GGx2a32VFdNImECb-A_qvo4kU5u9svagc4S5QYWdEno0D3rdstnnmaiwELRlKyM8j3o3n9uHzmE/s1600/Extra-Magic-Pandiagonal-Torus-16KM-diag-Order-7.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic "knight's tour" pandiagonal torus of order-7 has 16 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1579" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg8PNyaqYdk3e9meqBbTs1U0Ghyf2XBjqLqWKwOKNFSCgZZ8wi7kctPrj7YVPFHrl-2GGx2a32VFdNImECb-A_qvo4kU5u9svagc4S5QYWdEno0D3rdstnnmaiwELRlKyM8j3o3n9uHzmE/s200/Extra-Magic-Pandiagonal-Torus-16KM-diag-Order-7.png" title="" width="196" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic "Knight Tour" Pandiagonal Torus of Order-7 with 16 KM Magic Diagonals</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph is based on a <a href="https://www.mayhematics.com/t/2t.htm#Five-Square_Magic_Torus_Tours" rel="" target="_blank">"knight's tour"</a> pandiagonal Torus of Order-7 published by <a href="https://en.wikipedia.org/wiki/Emory_McClintock" rel="" target="_blank">Emory McClintock</a> in his 1896 paper <a href="https://www.jstor.org/stable/2369587?seq=1#metadata_info_tab_contents" rel="" target="_blank">"On the Most Perfect Forms of Magic Squares, with Methods for their Production"</a> (figure A): Although McClintock mentions "leaper" moves such as the <a href="https://en.wikipedia.org/wiki/Zebra_(chess)" rel="" target="_blank">Zebra</a> (3, -2) in the description of his construction method by "step summation", he does not point out the traditional knight move magic diagonal characteristics of his pandiagonal square. After the addition of the 16 knight move magic diagonals that we find on this torus, the maximum number of magic lines at a nodal intersection is 8 (at number node 25). The total number of magic lines on the pandiagonal torus is 14 orthogonals (in red) + 14 classic diagonals (in red) + 16 knight move diagonals (in blue) = 44 magic lines.</p>
<h3 style="text-align: justify;">Extra-Magic "Knight's Tour" Partially Pandiagonal Torus of Order-7<br />
with 22 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiQeJKJvaezSf8-87clOvOv6xunUpATnicJJ2K3PdYNKyy4W-FO04I6gSuRpvOIyAnpiy_PbII_Ue9QlPwWEklyynZMc_f-dVqjbWWzrCEUPCmRj08ORrldjOZ17wGeBv5S3_CnptnhKVY/s1600/Extra-Magic-P_Pandiagonal-Torus-22KM-diag-Order-7.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic "knight's tour" partially pandiagonal torus of order-7 has 22 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1568" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiQeJKJvaezSf8-87clOvOv6xunUpATnicJJ2K3PdYNKyy4W-FO04I6gSuRpvOIyAnpiy_PbII_Ue9QlPwWEklyynZMc_f-dVqjbWWzrCEUPCmRj08ORrldjOZ17wGeBv5S3_CnptnhKVY/s200/Extra-Magic-P_Pandiagonal-Torus-22KM-diag-Order-7.png" title="" width="195" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic "Knight Tour" Partially Pandiagonal Torus of Order-7 with 22 KM Magic Diagonals</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph is based on a <a href="http://www.mayhematics.com/t/2t.htm" rel="" target="_blank">"knight's tour"</a> partially pandiagonal torus of order-7 that <a href="http://www.mayhematics.com/o/my_chess.htm" rel="" target="_blank">George Jelliss</a> has kindly authorised me to use. After the addition of the 22 knight move magic diagonals, the maximum number of magic lines at a nodal intersection is 8 (at number node 25). George Jelliss points out that the <i>"geometry of 'straight lines' is distinctly non-euclidean."</i> For example, numbers such as (22, 23, 24, 25, 26, 27, 28) are connected in at least 3 different ways along <a href="https://en.wikipedia.org/wiki/Knight_%28chess%29#Placement_and_movement" rel="" target="_blank">knight</a> (1, 2), <a href="https://en.wikipedia.org/wiki/Camel_(chess)" rel="" target="_blank">camel</a> (3, -1), and <a href="https://en.wikipedia.org/wiki/Zebra_(chess)" rel="" target="_blank">zebra</a> (2, -3) move magic diagonals, and many more possibilities exist if we stretch out the knight move steps even further... But here we only take into account the traditional knight move magic diagonals, and the total number of magic lines on the partially pandiagonal torus is therefore 14 orthogonals (in red) + 8 classic diagonals (in red) + 22 knight move diagonals (in blue) = 44 magic lines.</p>
<h3 style="text-align: justify;">Extra-Magic Basic Magic Torus of Order-7<br />
with 28 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgR-6M4PVEWwPT7fYxOE9lLqqMPyPyHPYYPY1RtKalTOwBjB21kFyLjxmjWDuAl-pMTL0AZONuBk2gCw7EfYxBp-FECQYzz0vnKL4lpf9BPjZ30wgWVMq3L6E90BhBoX2tTaKuRpILPqVg/s1600/Extra-Magic-Basic-Magic-Torus-28KM-diag-Order-7.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic basic magic torus of order-7 is knight move pandiagonal." border="0" data-original-height="1600" data-original-width="1570" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgR-6M4PVEWwPT7fYxOE9lLqqMPyPyHPYYPY1RtKalTOwBjB21kFyLjxmjWDuAl-pMTL0AZONuBk2gCw7EfYxBp-FECQYzz0vnKL4lpf9BPjZ30wgWVMq3L6E90BhBoX2tTaKuRpILPqVg/s200/Extra-Magic-Basic-Magic-Torus-28KM-diag-Order-7.png" title="" width="196" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Basic Magic Torus of Order-7 with 28 KM Magic Diagonals</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph is based on a <i>knight move pandiagonal</i> basic magic torus of order-7 that Miguel Angel Amela has kindly authorised me to use. This torus was probably created when he wrote his paper <a href="https://drive.google.com/file/d/1Jr8OXTQbL1LewxZq5o0w4x-Nt7QpJoDo/view?usp=sharing" rel="" target="_blank">"Magic and Semi-Magic Squares of Order 5 - Rectangular Pandiagonality"</a> in spring 2011. After the addition of the knight move magic diagonals, the maximum number of magic lines at a nodal intersection is 8 (at number node 25). The total number of magic lines on the basic magic torus is 14 orthogonals (in red) + 2 classic diagonals (in red) + 28 knight move diagonals (in blue) = 44 magic lines.</p>
<h2 style="text-align: justify;">An Extra-Magic Semi-Magic Torus of Order-7</h2>
<p style="text-align: justify;"><i>Extra-magic semi-magic tori of order-7 have neither been fully investigated nor precisely counted, and the example shown below is randomly chosen.</i></p>
<h3 style="text-align: justify;">Extra-Magic Semi-Magic Torus of Order-7<br />
with 6 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjY0MnsaG1qihfN2e4JWvGCB3_ncHBq1xs8j3tpdmFCvq7H6L9rbSHimarrwKiTd2T5ixfESsd8-7Ki_C_u1Ge_Hf8iA5yRxvkonsRQnFblGgjoms89cVu272n4ulldTJP4xKLwei1CW1k/s1600/Extra-Magic-Semi-Magic-Torus-6KM-diag-Order-7.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic semi-magic torus of order-7 has 6 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1570" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjY0MnsaG1qihfN2e4JWvGCB3_ncHBq1xs8j3tpdmFCvq7H6L9rbSHimarrwKiTd2T5ixfESsd8-7Ki_C_u1Ge_Hf8iA5yRxvkonsRQnFblGgjoms89cVu272n4ulldTJP4xKLwei1CW1k/s200/Extra-Magic-Semi-Magic-Torus-6KM-diag-Order-7.png" title="" width="196" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Semi-Magic Torus of Order-7 with 6 KM Magic Diagonals</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph of a semi-magic torus of order-7 shows the presence of 6 knight move magic diagonals. The maximum number of magic lines at a nodal intersection is 5 (at number nodes 12, 28, 35 and 39). The total number of magic lines on the semi-magic torus is 14 orthogonals (in red) + 3 classic diagonals (in red) + 6 knight move diagonals (in blue) = 23 magic lines.</p>
<h2 style="text-align: justify;">Extra-Magic Tori of Order-8</h2>
<p style="text-align: justify;">Of the same format as traditional <a href="https://en.wikipedia.org/wiki/Chessboard" rel="" target="_blank">chessboards</a>, magic squares of order-8 have not only been the focus of much previous research into <a href="http://mayhematics.com/t/1a.htm" rel="" target="_blank">"knights' tours"</a>, <i>but have also been (since 1877, if not earlier) the subject of studies of knight move magic diagonals.</i> Further historical details are given in the observations made after the analysis of a "Caïssan Beauty", studied below.</p>
<p style="text-align: justify;">Only consecutively numbered magic tori (<i>with numbers from 1 to n²</i>) are studied here, and consequently, for the <i>order-8</i>, the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> <i>MC = 260</i>.</p>
<p style="text-align: justify;"><i>Extra-magic tori of order-8 have neither been fully investigated nor precisely counted, and the examples shown below are selected samples of some of the different varieties.</i></p>
<h3 style="text-align: justify;">Extra-Magic "Caïssan Beauty" Pandiagonal Torus of Order-8<br />
with 64 Extra-Magic Intersections and 32 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBDth6qPLOrLnppQvkXU3BHTIcgm1uuSkt0QO1RS_mgkxritSzPy9leJMyvQZ8eRMlZfKrYbxsbu0-h-Ig92lFjyh_Ki08_xbKFvWyF34R6r4_BvhxZOztTP2RZSvhmHpV1Jzlbss7X34/s1600/Extra-Magic-Caissan-Beauty-Torus-32KM-diag-Order-8.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic "Caïssan Beauty" pandiagonal torus of order-8 has 64 extra-magic intersections and is also knight move pandiagonal." border="0" data-original-height="1598" data-original-width="1600" height="199" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBDth6qPLOrLnppQvkXU3BHTIcgm1uuSkt0QO1RS_mgkxritSzPy9leJMyvQZ8eRMlZfKrYbxsbu0-h-Ig92lFjyh_Ki08_xbKFvWyF34R6r4_BvhxZOztTP2RZSvhmHpV1Jzlbss7X34/s200/Extra-Magic-Caissan-Beauty-Torus-32KM-diag-Order-8.png" title="" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic "Caïssan Beauty" Pandiagonal Torus of Order-8 with 32 KM Magic Diagonals</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph, based on a "Caïssan Beauty" pandiagonal torus of order-8 created by <a href="https://en.wikipedia.org/wiki/Narayana_Pandita" rel="" target="_blank">Nārāyana Pandita</a> (Sanskrit: <span style="font-size: x-small;">नारायण पण्डित</span>) in 1356, shows the presence of 64 extra-magic intersections as well as knight move pandiagonality. The maximum number of magic lines at nodal intersections is 8 (at all number nodes). The total number of magic lines on the "Caïssan Beauty" pandiagonal torus is 16 orthogonals (in red) + 16 classic diagonals (in red) + 32 knight move diagonals (in blue) = 64 magic lines.</p>
<p style="text-align: justify;">First published by Nārāyana Pandita in his 1356 <a href="https://en.wikipedia.org/wiki/Ganita_Kaumudi" rel="" target="_blank">"Gaṇita Kaumudī"</a> (Part II), an original version of the torus can be seen <a href="https://archive.org/details/ganithakoumudipa015625mbp/page/n395" rel="" target="_blank">online</a>, on page 396 of a 1942 reprint. Only those versed in Sanskrit will be able to read whether Nārāyana Pandita mentioned the knight move pandiagonal characteristics.</p>
<p style="text-align: justify;">What we know for sure is that in 1877, <a href="https://en.wikisource.org/wiki/Author:Andrew_Hollingworth_Frost" rel="" target="_blank">Andrew Hollingworth Frost</a> wrote an article <a href="https://books.google.ca/books?id=qxMLAAAAYAAJ&hl=fr&pg=PA48#v=onepage&q&f=false" rel="" target="_blank">"On the General Properties of Nasik Squares"</a> in "The Quarterly Journal of Pure and Applied Mathematics", Volume 15, in which he presented <i>the same Nārāyana Pandita torus <a href="https://carresmagiques.blogspot.com/2020/04/from-magic-square-to-magic-torus.html" target="_blank">seen from a different magic square viewpoint</a></i>, referring to a <a href="https://drive.google.com/file/d/1JtsR55ISdhHoTbv9ZXQ26UErWOqgjd0K/view?usp=sharing" rel="" target="_blank">diagram <i>S</i></a> in his description: <i>"By the method adopted in No. XXV. 1865, of this Journal, squares of the form 4n had four summations only, in the lines of the row [sic], columns, and diagonals. This square has ten summations through each number, as shewn in the diagram S, the hollow dots giving the pathlets of contsruction [sic]."</i> After verification of the <a href="https://drive.google.com/file/d/1JtsR55ISdhHoTbv9ZXQ26UErWOqgjd0K/view?usp=sharing" rel="" target="_blank">diagram <i>S</i></a>, we see that it shows 2 orthogonal pathlets, 2 diagonal (1, 1) pathlets, 2 diagonal (1, 2) pathlets, 2 diagonal (2, 1) pathlets, 2 diagonal (1, 3) pathlets = 10 pathlets! Although this is a clearly documented example of the early awareness of knight move magic diagonals, Frost may have been preceded by others... </p><p style="text-align: justify;">Please note that the initial intention of the present article "Extra-Magic Tori and Knight Move Magic Diagonals" was to limit the study to classic knight moves, and it was only because Frost had integrated (1, 3) leaper pathlets in his Diagram S, that it was decided to make an exception for the analysis of the Caïssan Beauty, and additionally count camel moves for this particular case. However, Frost only takes into account 2 out of the 4 camel move diagonal (1, 3) pathlets, ignoring the dissimilar paths that use a same magic series... And in the present article we count separately the same-series pathlets having different magic sequences and dissimilar paths, <i>so our count gives a total of 12 pathlets</i>. Please refer to "Knight Move Magic Diagonals", at the beginning of the blog article, where this phenomena is already pointed out and a link is provided towards a file dated 7th August 2019, entitled <a href="https://drive.google.com/file/d/1gFx_JklpK_jKiLbgod142mR_ayXYXl1K/view" target="_blank">"Knight Move Magic Diagonals on Magic Tori"</a>. The file explains why knight move (and by extrapolation, other leaper move magic diagonals) can have 2 different paths for a same series of numbers.<br /></p>
<p style="text-align: justify;">In 1881, <a href="http://math.ut.ee/acta/16-1/Styan.pdf#1.4._%60%60Ursus'':_Henry_James_Kesson%20(b.%20c.%201844)" rel="" target="_blank">"Ursus" (Henry James Kesson?)</a> wrote an article entitled <a href="http://www.math.mcgill.ca/styan/QCU-15jan11-opt" rel="" target="_blank">"Caïssan Magic Squares"</a> in "The Queen, The Lady's Newspaper & Court Chronicle", presenting <i>the same Nārāyana Pandita torus</i>,<a href="https://carresmagiques.blogspot.com/2020/04/from-magic-square-to-magic-torus.html" target="_blank">seen from yet another magic square viewpoint</a>, in his Figure D. "Ursus" was clearly aware of all the chess move magic diagonals, and he defined a magic square to be Caïssan whenever it was pandiagonal and knight-Nasik. "Ursus" seems to have been the first person to explicitly connect "Caïssa" (named as the <i>patron goddess</i> of chess players by <a href="https://en.wikipedia.org/wiki/William_Jones_(philologist)" rel="" target="_blank">Sir William Jones</a> in his 1763 <a href="https://en.wikipedia.org/wiki/William_Jones_(philologist)#Chess_poem" rel="" target="_blank">"Caïssa, or The Game at chess, a poem"</a>) with magic squares.</p>
<p style="text-align: justify;">In 1900, <a href="http://multimagie.com/English/Planck.htm" rel="" target="_blank">Charles Planck</a> wrote an article entitled <a href="https://drive.google.com/file/d/1lNIMf39ps8eWCaPRXFw1hp-OWHiL9fi2/view?usp=sharing" rel="" target="_blank">"The <i>n</i> queens problem"</a> in "The British Chess Magazine", and presented <i>the same Nārāyana Pandita torus</i>, <a href="https://carresmagiques.blogspot.com/2012/03/from-magic-square-to-magic-torus.html" rel="" target="_blank">seen from a once again different magic square viewpoint</a> in his Figure II, stating that he believed it to be the <i>"first complete Caïssan square of 64 cells which has been constructed"</i>!</p>
<p style="text-align: justify;">Although the different magic square viewpoints of Nārāyana Pandita's original that were presented by these distinguished authors were certainly coincidental, it is a relief to find at least one writer of the same period who produced two totally original "Caissan Beauties": In 1896, <a href="https://en.wikipedia.org/wiki/Emory_McClintock" rel="" target="_blank">Emory McClintock</a> presented a paper to the American Mathematical Society entitled <a href="https://www.jstor.org/stable/pdf/2369587.pdf" rel="" target="_blank">"On the Most Perfect Forms of Magic Squares, with Methods for their Production"</a> in which his squares D and E were refreshingly new examples, both coming from completely different "Caïssan Beauty" pandiagonal tori. </p>
<p style="text-align: justify;"><a href="https://www.math.mcgill.ca/styan/" rel="" target="_blank">George P. H. Styan</a> has written an excellent paper entitled <a href="http://193.40.22.10/index.php/ACUTM/article/view/ACUTM.2012.16.07/12066" rel="" target="_blank">"An illustrated introduction to Caïssan squares: the magic of chess"</a>. Published in 2012, in Volume 16, Number 1, of <a href="https://tyk.ee/acutm" rel="" target="_blank">"Acta et Commentationes Universitatis Tartuensis de Mathematica"</a> it retraces the history of Caïssan squares in great detail with numerous references, and I fully recommend it to readers who wish to learn more.</p>
<h3>Extra-Magic Partially Pandiagonal Torus of Order-8<br />
with 32 Extra-Magic Intersections and 4 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrGN6yA811smi7qYbBebzdN6JPEfF1NRxPedWEMG9NLR6G5ZB23v6g_tBZXornLsS6brojlatFNYIUe8HTlXxuRZM3dWMzVAOUi25rRs_bOFBihcm-mrpE9iwTsy1EtJYb8K5i05DHo4I/s1600/Extra-Magic-P_Pandiagonal-Torus-4KM-diag-Order-8.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic partially pandiagonal torus of order-8 has 32 extra-magic intersections and 4 knight move magic diagonals." border="0" data-original-height="1600" data-original-width="1600" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrGN6yA811smi7qYbBebzdN6JPEfF1NRxPedWEMG9NLR6G5ZB23v6g_tBZXornLsS6brojlatFNYIUe8HTlXxuRZM3dWMzVAOUi25rRs_bOFBihcm-mrpE9iwTsy1EtJYb8K5i05DHo4I/s200/Extra-Magic-P_Pandiagonal-Torus-4KM-diag-Order-8.png" title="" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Partially Pandiagonal Torus of Order-8 with 4 KM Magic Diagonals</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph, based on a partially pandiagonal torus of order-8 which <a href="http://www.trump.de/magic-squares/" rel="" target="_blank">Walter Trump</a> has kindly authorised me to use, shows not only the presence of 32 extra-magic intersections but also 4 knight move magic diagonals. (The torus is also bimagic, but the squared version has no such diagonals). After the addition of the knight move magic diagonals, the maximum number of magic lines at a nodal intersection is 5 (at 16 number nodes 6, 7, 14, 15, 22, 23, 30, 31, 34, 35, 42, 43, 50, 51, 58, 59). The total number of magic lines on the partially pandiagonal torus is 16 orthogonals (in red) + 12 classic diagonals (in red) + 4 knight move diagonals (in blue) = 32 magic lines.</p>
<h2 style="text-align: justify;">Extra-Magic Semi-Magic Torus of Order-8</h2>
<p style="text-align: justify;"><i>Extra-magic semi-magic tori of order-8 have neither been fully investigated nor precisely counted, and although only one of many, the example below is specifically chosen for its historical importance.</i> </p>
<h3 style="text-align: justify;">Extra-Magic Semi-Magic "Knight's Tour" Torus of Order-8<br />
with 2 Knight Move Magic Diagonals</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg47C91L0Nchtb00g0xfVWWez9KpdfERs9RdD2Bm7H5qvkhogVoQjNaDVVgkIxq6N8O1irYX0OEa6Cb4VX96PvycJ-oCv7joq1Qt75HlYCq8syvY1SUxrxIFeftwD3Pmbl4O5x6USAL-hk/s1600/Extra-Magic-Semi-Magic-Torus-2KM-diag-Order-8.png" style="margin-left: auto; margin-right: auto;"><img alt="This extra-magic semi-magic "knight's tour" torus of order-8 has 2 knight move magic diagonals." border="0" data-original-height="1598" data-original-width="1600" height="199" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg47C91L0Nchtb00g0xfVWWez9KpdfERs9RdD2Bm7H5qvkhogVoQjNaDVVgkIxq6N8O1irYX0OEa6Cb4VX96PvycJ-oCv7joq1Qt75HlYCq8syvY1SUxrxIFeftwD3Pmbl4O5x6USAL-hk/s200/Extra-Magic-Semi-Magic-Torus-2KM-diag-Order-8.png" title="" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Extra-Magic Semi-Magic "Knight Tour" Torus of Order-8 with 2 KM Magic Diagonals</span></td></tr>
</tbody></table>
<p style="text-align: justify;">This magic line graph is based on the first semi-magic knight's tour torus that was created by <a href="https://en.wikipedia.org/wiki/William_Roxby_Beverly#Works" rel="" target="_blank">William Roxby Beverley</a> and published as a letter dated 5th June 1847 <a href="https://books.google.ch/books?id=jc1eAAAAcAAJ&pg=PA344&dq=%22William+Beverley%22+intitle:chess&hl=fr&sa=X&ved=0ahUKEwjIsuSchsfUAhUDnBoKHZdRAlwQ6AEILDAB#v=onepage&q&f=false" rel="" target="_blank">"On the Magic Square of the Knight's March"</a> in the August 1848 edition of "The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science". After the addition of the knight move magic diagonals, the maximum number of magic lines at a nodal intersection is 3 (at 16 number nodes 7, 8, 9, 10, 33, 34, 35, 36, 37, 38, 43, 44, 45, 46, 46, and 48). The total number of magic lines on the semi-magic torus is 16 orthogonals (in red) + 0 classic diagonals (in red) + 2 knight move diagonals (in blue) = 18 magic lines. </p>
<p style="text-align: justify;">More information about William Beverley is given in the <a href="http://mayhematics.com/t/1d.htm#(1)" rel="" target="_blank">"History of Knight Tours"</a> and <a href="http://www.mayhematics.com/t/1n.htm#(7)" rel="" target="_blank">"Magic Knight Tours"</a> by <a href="https://www.mayhematics.com/o/my_chess.htm" rel="" target="_blank">George Jelliss</a>. At this stage it is useful to point out that Beverley's first semi-magic knight's tour square of order-8 has sometimes been mistakenly attributed to <a href="https://en.wikipedia.org/wiki/Leonhard_Euler" rel="" target="_blank">Leonhard Euler</a> by otherwise reputable sources, and although Euler did indeed present knights' tours in his <a href="http://www.bibnum.education.fr/euler-et-le-parcours-du-cavalier-dans-une-grille-rectangulaire" rel="" target="_blank">"Solution d'une question curieuse qui ne paroit soumise a aucune analyse"</a> which was published in 1759, none of his solutions were either semi-magic or magic! </p>
<h2 style="text-align: justify;">Observations</h2>
<br />
<h3 style="text-align: justify;">The Impact of Knight Move Magic Diagonals </h3>
<p style="text-align: justify;">Once we take knight move magic diagonals into account, this can modify our perception of the "most magic" solutions. In this study we have only used traditional knight move steps and there are already many examples with a dense weave of magic lines. What a magic line graph looks like after the addition of non-traditional knight move lines is difficult to say, but we can anticipate that in several cases there will be very little blank space, or even none whatsoever...</p>
<p style="text-align: justify;">In order-4, we immediately notice that the total number of magic lines of a pandiagonal torus type T4.01 (which has 12 magic lines) is inferior to the total number of lines of the extra-magic semi-pandiagonal torus type n° T4.02.3 (which has 20 magic lines). Also, 2 out of 6 partially pandiagonal tori type T4.03.1, and each of the partially pandiagonal tori types T4.03.2 and T4.03.3 have 16 magic lines, which is more than the number of magic lines of a pandiagonal torus type T4.01. Even the basic magic tori with knight move magic diagonals have a greater number of magic lines than the pandiagonal torus: 4 of the basic magic tori type T4.05.1 have 14 magic lines and 6 have 18 magic lines, whist 2 of the basic magic tori type T4.05.2 again have 14 magic lines. What is perhaps more surprising is that semi-magic tori such as the torus types T4.06.0A and T4.07.0A have respectively 20 and 14 magic lines; both examples exceeding the pandiagonal torus T4.01 in their magic line totals. The semi-magic torus type T4.06.0A even equals the highest number of magic lines of the "most magic" semi-pandiagonal torus type T4.02.3! As the semi-magic tori of order-4 have not yet been explored in detail, there may be other "more magic" cases that remain to be discovered...</p>
<p style="text-align: justify;">In order-5, there are also surprises, and without going into all the detail it can be seen that a basic magic torus type T5.10 with knight move pandiagonality has a total of 32 magic lines, which is many more than that of a pandiagonal torus type T5.01, which only has 6 knight move diagonals and a total of 26 magic lines. The order-5 has not been completely explored, so there may be other cases that will modify our appreciation of which tori are the "most magic".</p>
<p style="text-align: justify;">In order-6, there are no pandiagonal tori when using consecutive numbers from <i>1 to n²</i>, as <a href="http://multimagie.com/English/Planck.htm" rel="" target="_blank">Charles Planck</a> proved in his 1919 Monist article <a href="https://www.jstor.org/stable/27900742?seq=1#metadata_info_tab_contents" rel="" target="_blank">"Pandiagonal Magics of Orders 6 and 10 with Minimal Numbers"</a>. In the magic line graphs that are illustrated here, a partially pandiagonal example with 4 knight move magic diagonals has 24 magic lines; a basic magic example with 2 knight move magic diagonals has 16 magic lines; and a compact <i>semi-magic</i> example with knight move pandiagonality has 36 magic lines! Another semi-magic example worthy of interest is the torus with 1 knight move magic diagonal, and 2 extra-magic intersections of 6 magic lines, giving a total of 15 magic lines: This also exceeds the total number of magic lines of a "regular" basic magic torus of order-6, which, with 12 orthogonals + 2 diagonals, has only 14 magic lines.</p>
<p style="text-align: justify;">In order-7, a "knight's tour" pandiagonal torus with 16 knight move magic diagonals, a "knight's tour" partially pandiagonal torus with 22 knight move magic diagonals, and a basic magic torus that is knight move pandiagonal, all have the same total of 44 magic lines.</p>
<p style="text-align: justify;">In order-8, the "Caïssan Beauty" with 64 = <i>n²</i> magic lines is a pure marvel for both magic square and chess enthusiasts!</p>
<p style="text-align: justify;">It can be seen that semi-magic tori (and the semi-magic squares that they display) often rival, and sometimes even better their magic tori cousins when we include the knight move magic diagonals in the counts of the magic lines. A reappraisal of the definitions seems to be called for. Both magic and semi-magic tori have almost similar magic weaves, so logically no hard distinction should be made between them.</p>
<h3 style="text-align: justify;">Knight Move Bimagic Diagonals</h3>
<p style="text-align: justify;">In the squared version of the extra-magic partially pandiagonal torus of order-8 (with 32 extra-magic intersections and 4 knight move magic diagonals) tested above, it was disappointing to find no knight move bimagic diagonals. When testing another likely candidate , the order-32 square constructed by <a href="http://multimagie.com/English/Panbimagic.htm#SuMaoting" rel="" target="_blank">Su Maoting</a> in February 2006 (which is the first known normal pandiagonal bimagic square using consecutive integers, and downloadable from Christian Boyer's <a href="http://www.multimagie.com/" rel="" target="_blank">Multimagic Squares</a> site), it turns out to have 64 knight move magic diagonals, but once again, none of these are bimagic.</p>
<p style="text-align: justify;">It is therefore still an open question as to whether knight move bimagic diagonals exist on bimagic tori, and if so, whether there are cases with knight move bimagic pandiagonality.</p>
<h3 style="text-align: justify;">The Geometry of Knight Move Lines</h3>
<p style="text-align: justify;">It is interesting to note that when 3 traditional knight move magic lines form a triangle, then this triangle will always be Pythagorean, with a 3 : 4 : 5 proportion. This and other observations on knight move geometry are discussed further on the web page <a href="https://www.mayhematics.com/t/2g.htm" rel="" target="_blank">"Geometry of Knight's Moves"</a> by <a href="http://mayhematics.com/t/t.htm" rel="" target="_blank">George Jelliss</a>. The geometry of other non-traditional "leapers" can be found on two more of his pages: <a href="https://www.mayhematics.com/t/2a.htm#(2)" rel="" target="_blank">"Theory of Moves"</a> and <a href="https://www.mayhematics.com/t/2b.htm" rel="" target="_blank">"Theory of Journeys"</a>.</p>
<h2>Acknowledgements</h2>
<p style="text-align: justify;">
My special thanks go to <a href="http://www.multimagie.com/AmelaPIBMS.pdf" rel="" target="_blank">Miguel Angel Amela</a>, for his invaluable assistance in the search for previous documentation on knight move magic diagonals, and for taking the time to check and confirm my findings concerning the knight move magic diagonals of the magic tori of order-4. Miguel has also kindly authorised me to append his papers <a href="https://drive.google.com/file/d/1Jr8OXTQbL1LewxZq5o0w4x-Nt7QpJoDo/view?usp=sharing" rel="" target="_blank">"Magic and Semi-Magic Squares of Order 5 - Rectangular Pandiagonality"</a> and <a href="https://drive.google.com/file/d/1OWkPeS_9wOud9EdWGzrAfEabuFxdaDKr/view?usp=sharing" rel="" target="_blank">"Compact Magic and Semi-Magic Squares of Order n = 4k+2 - Rectangular Pandiagonality"</a> to this post, and has given me his permission to use his knight move pandiagonal squares of orders 5, 6 and 7 for magic line graphs.</p>
<p style="text-align: justify;">
Although, to the best of my knowledge, all of the magic line graphs illustrated here are original, many of them are based on magic squares or magic tori that have been constructed by others:</p>
<p style="text-align: justify;">
In the public domain we find the Lo Shu magic square of order-3 by <a href="https://en.wikipedia.org/wiki/Anonymous_work#Explanations" rel="" target="_blank">Anonymus</a>, and the magic squares of order-4, once again by <a href="https://en.wikipedia.org/wiki/Anonymous_work#Explanations" rel="" target="_blank">Anonymus</a> (but first listed by <a href="https://en.wikipedia.org/wiki/Bernard_Fr%C3%A9nicle_de_Bessy" rel="" target="_blank">Bernard Frénicle de Bessy</a>). Also coming from the public domain, because they were published before 1923, other magic squares used here include a pandiagonal square of order-5 attributed to <a href="https://fr.wikipedia.org/wiki/Philippe_de_La_Hire" rel="" target="_blank">Philippe de la Hire</a> by <a href="https://en.wikipedia.org/wiki/Percy_Alexander_MacMahon" rel="" target="_blank">Percy Alexander MacMahon</a>; a "knight's tour" partially pandiagonal square of order-5 together with a basic magic square of order-6 by <a href="https://en.wikipedia.org/wiki/William_Symes_Andrews" rel="" target="_blank">William Symes Andrews</a>; a "knight's tour" pandiagonal square of order-7 by <a href="https://en.wikipedia.org/wiki/Emory_McClintock" rel="" target="_blank">Emory McClintock</a>; a "Caïssan Beauty" pandiagonal square of order-8 created by <a href="https://en.wikipedia.org/wiki/Narayana_Pandita" rel="" target="_blank">Nārāyana Pandita</a>; and a "knight's tour" semi-magic square by <a href="https://en.wikipedia.org/wiki/William_Roxby_Beverly#Works" rel="" target="_blank">William Roxby Beverley</a>. Each of these authors deserves to be remembered.</p>
<p style="text-align: justify;">
Contributions of other magic tori or magic squares, by the magic square specialists of today, include (in the order of the authors' appearance) the semi-magic tori T4.06.0A and T4.07.0A of order-4, the partially pandiagonal tori T5.03.00A T5.04.000A of order-5, a semi-magic torus of order-6, and a partially pandiagonal bimagic torus of order-8 by <a href="http://www.trump.de/magic-squares/" rel="" target="_blank">Walter Trump</a>; a basic magic torus T5.10 of order-5, a compact semi-magic torus of order-6, and a basic magic torus of order-7 (all knight move pandiagonal) by <a href="https://budshaw.ca/documents/6-SOLS%209x9.pdf" rel="" target="_blank">Miguel Angel Amela</a>; a partially pandiagonal torus of order-6 by <a href="https://budshaw.ca/MagicSquares.html" rel="nofollow" target="_blank">Harry White</a>; a partially pandiagonal torus of order-6 by <a href="https://www.gaspalou.fr/magic-squares/index.htm" rel="" target="_blank">Francis Gaspalou</a>; and a "knight's tour" partially pandiagonal torus of order-7 by <a href="http://www.mayhematics.com/o/my_chess.htm" rel="" target="_blank">George Jelliss</a>. My hearty thanks go to each of these authors for allowing me to use their work. Without their contributions, certain magic line graphs of this paper would not have been possible.</p>
<p style="text-align: justify;">
The sites that host the hyperlinked documentation include (in the order of their "appearance") <a href="https://primepuzzles.net/" rel="" target="_blank">Prime Puzzles</a>, <a href="https://www.wikipedia.org/" rel="" target="_blank">Wikipedia</a>, <a href="https://books.google.fr/" rel="" target="_blank">Google Books</a>, <a href="https://www.nature.com/" rel="" target="_blank">Nature</a>, <a href="https://archive.org/" rel="" target="_blank">Internet Archive</a>, <a href="https://www.jstor.org/" rel="" target="_blank">JStor</a>, <a href="http://www.mayhematics.com/" rel="" target="_blank">Mayhematics</a>, <a href="https://en.wikisource.org/" rel="" target="_blank">Wikisource</a>, <a href="https://www.math.ut.ee/en" rel="" target="_blank">The University of Tartu</a>, <a href="https://www.mcgill.ca/mathstat/" rel="" target="_blank">McGill University</a>, <a href="http://multimagie.com/" rel="" target="_blank">Multimagic Squares</a>, and <a href="http://www.bibnum.education.fr/" rel="" target="_blank">Bibnum Education</a>.</p>
<h2>Latest Developments</h2>
<p style="text-align: justify;">On the 20th August 2019 <a href="http://boingboing.net/2011/10/17/interview-with-futility-closet-blogger-greg-ross.html" rel="" target="_blank">Greg Ross</a> published an article entitled <a href="https://www.futilitycloset.com/2019/08/20/magicker/" rel="" target="_blank">"Magicker"</a> on the subject of knight move magic diagonals in his <a href="https://www.futilitycloset.com/2019/08/20/magicker/" rel="" target="_blank">Futility Closet</a> - An Idler's Miscellany of Compendious Amusements. </p>
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-36381340599632383132019-06-20T16:46:00.007+02:002023-07-03T17:49:55.760+02:00Pan-Zigzag Magic Tori Magnify the "Dürer" Magic Square<p style="text-align: justify;">The subject of pan-zigzag magic squares was first brought to my attention by <a href="http://budshaw.ca/ZigZag.html" target="_blank">Harry White</a>, who forwarded an e-mail with a pan-zigzag example inspired by the <a href="http://www.taliscope.com/Durer_en.html" target="_blank">"Dürer" Magic Square</a>, that Paul Michelet had sent to him on the 15th May 2019. </p>
<p style="text-align: justify;"><a href="https://www.magischvierkant.com/two-dimensional-eng/6x6/paul-michelet-s-trick/" target="_blank">Paul Michelet</a>, a chess endgame and problem composer, had constructed a magic torus of order-8 that was pan-zigzag, by replacing the entries of the "Dürer" Magic Square with consecutively numbered 2 x 2 squares.</p>
<p style="text-align: justify;">The objective of the present study is to find higher-orders of pan-zigzag magic tori that are direct descendants of both the "Dürer" magic torus of order-4, and the "Michelet" pan-zigzag magic torus of order-8.</p>
<br />
<h3 style="text-align: justify;">Pan-Zigzag Descendants of the Magic Torus that displays the "Dürer" Magic Square </h3>
<p style="text-align: justify;">In Paul Michelet's solution that follows, the 2 x 2 squares "magnify" the <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" rel="" target="_blank">T4.077 magic torus of order-4</a> that displays the "Dürer" Magic Square:</p>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_HWVZKAM6Qsw84DH3Uw5gy6pLvR4yro0-8_OWx8tXKvQAaystifDtIiBYnfKOb-LkhxW9xF71A3fgHaCmOWLVsFqbOsInBP-nuIxKm5_qBRlvSXCmMpGxXjxyZKSKVOPDCSUT0qqP5Ig/s1600/Durer_4_og.png" style="margin-left: auto; margin-right: auto;"><img alt="The traditional "Dürer" magic square of order-4 that is portrayed in "Melencolia I"" border="0" data-original-height="354" data-original-width="671" height="115" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_HWVZKAM6Qsw84DH3Uw5gy6pLvR4yro0-8_OWx8tXKvQAaystifDtIiBYnfKOb-LkhxW9xF71A3fgHaCmOWLVsFqbOsInBP-nuIxKm5_qBRlvSXCmMpGxXjxyZKSKVOPDCSUT0qqP5Ig/s200/Durer_4_og.png" title="" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">The order-4 magic torus T4.077</span><br />
<span style="font-size: x-small;">that displays the "Dürer" magic square.</span><br />
<span style="font-size: x-small;">The red dots show the 4 magic diagonals.</span><br />
<span style="font-size: x-small;">The magic constant (MC) is 34.</span></td></tr>
</tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUfywVDs8sxgiy5-a_Mc5FdVgene-Pskz7K4ghQqa3u2g45Aj6o4EVn26Hm7UNQXEn83xAz1ivYmf40yyj5n1eyj97wPMa0CXCptoJiTvK3zfxblG5GYZbZltt0s3aQWNfDXNwavLFrK0/s1600/Durer_order-8_PKMZZ_magic_t.png" style="margin-left: auto; margin-right: auto;"><img alt="The "Michelet" order-8 magic torus that magnifies the "Dürer" magic square of order-4 by using 2 x 2 squares" border="0" data-original-height="614" data-original-width="675" height="195" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUfywVDs8sxgiy5-a_Mc5FdVgene-Pskz7K4ghQqa3u2g45Aj6o4EVn26Hm7UNQXEn83xAz1ivYmf40yyj5n1eyj97wPMa0CXCptoJiTvK3zfxblG5GYZbZltt0s3aQWNfDXNwavLFrK0/s320/Durer_order-8_PKMZZ_magic_t.png" title="" width="195" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">The "Michelet" order-8 pan-zigzag magic torus,<br />
which is a <i>magnified</i> descendant of the "Dürer" magic torus T4.077.<br />
The red dots show the 4 magic diagonals. The magic constant (MC) is 260.</span> </td></tr></tbody></table>
<p style="text-align: justify;">
In the order-8 pan-zigzag example illustrated above, each of the entries of the "Dürer" magic square are replaced by consecutively numbered 2 x 2 squares. The resulting <a href="https://carresmagiques.blogspot.com/2020/04/from-magic-square-to-magic-torus.html" target="_blank">magic torus</a> has four magic diagonals that produce 8 magic intersections <i>and therefore eight essentially different magic squares</i>. All of the vertical zigzags, such as 61, 62, 20, 19, 33, 34, 16, 15, or 64, 63, 17, 18, 36, 35, 13, 14, add up to the <a href="https://en.wikipedia.org/wiki/Magic_constant" target="_blank">magic constant</a> of 260, and all of the horizontal zigzags, such as 64, 63, 9, 10, 5, 6, 52, 51, or 62, 61, 11, 12, 7, 8, 50, 49, also add up to 260. This magic torus is therefore <i>pan-4-way V zigzag<sub>2</sub></i>. Harry White states that <i>V zigzag<sub>2</sub></i> magic squares are also <i>V zigzagA<sub>2,3,4,5...n</sub></i>, and underlines the fact that <i>V zigzagA<sub>2</sub></i> is the same as <i>V zigzag<sub>2</sub></i>. It should be noted that the <i>V zigzagA<sub>3</sub></i> waves are <i>knight moves</i>, and in correspondence with <a href="http://magictesseract.com./large_squares" rel="" target="_blank">Dwane Campbell</a> (who has also written about <a href="http://magictesseract.com./large_squares" rel="" target="_blank">zigzag patterns</a>), Harry White points out that "every magic square that has the <i>Zigzag<sub>2</sub></i> property in both rows and columns will also have the <i>Pan Knight Move property</i>." In addition to the <i>pan-4-way V zigzag<sub>2</sub></i> characteristics already mentioned above, this magic torus is also <i>U zigzag 2-way (up, down)</i>. For more details of these classifications please refer to Harry White's <a href="http://budshaw.ca/ZigZag.html" target="_blank">Zigag Magic Squares</a> page.</p>
<p style="text-align: justify;">The sums of each of the N/4 x N/4 subsquares of the "Michelet" magic torus of order-8 are related to those of the original "Dürer" magic torus of order-4:</p>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7lPELbjfRe7oMA1ncCatNxJ_xE65LIkeQLvSGeDS2cr2_NFRDghhqEH3DL5zYME2vmNicdjq6IAVlr-MC3WOiPwzi_LN-Rnrf0hRgpwI9Y9j0VUKHU-2PmCIRyg2LlwLEbTsafBAdUfI/s1600/Durer_orders_4_8_subsquares.png" style="margin-left: auto; margin-right: auto;"><img alt="The 16 subsquares of the "Dürer" magic torus of order-4 and of the descendant "Michelet" magic torus of order-8." border="0" data-original-height="538" data-original-width="1463" height="145" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7lPELbjfRe7oMA1ncCatNxJ_xE65LIkeQLvSGeDS2cr2_NFRDghhqEH3DL5zYME2vmNicdjq6IAVlr-MC3WOiPwzi_LN-Rnrf0hRgpwI9Y9j0VUKHU-2PmCIRyg2LlwLEbTsafBAdUfI/s400/Durer_orders_4_8_subsquares.png" title="" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">The totals of the 16 subsquares of the T4.077 "Dürer" magic torus of order-4 compared with<br />
those of the 16 subsquares of the "Michelet" magnified magic torus descendant of order-8.</span></td></tr></tbody></table>
<p style="text-align: justify;">
For more examples of pan-zigzag magic tori that continue to magnify the "Durer" magic square <i>in higher-orders</i>, the complete paper is below. Please note that although the preview page does not display the hyperlinks, these are accessible when you download <a href="https://docs.google.com/uc?export=download&id=1QDRH36_Kos_H9Zw4TXeViHT_aOx4FTCk" target="_blank">Pan-Zigzag Torus Descendants that Magnify the "Durer" Magic Square:</a></p>
<iframe height="715px" src="https://docs.google.com/viewer?srcid=1QDRH36_Kos_H9Zw4TXeViHT_aOx4FTCk&pid=explorer&efh=false&a=v&chrome=false&embedded=true" width="518px"></iframe>
<br />
<br />
<br />
<h3 style="text-align: justify;">Latest Development</h3>
<p style="text-align: justify;"><a href="https://www.researchgate.net/profile/Peter-Loly" target="_blank">Peter D. Loly</a>, a senior scholar of the Department of Physics and Astronomy of the University of Manitoba, has kindly analysed the « Michelet » pan zigzag square of order-8, using the critical tools developed since the publication of <i><a href="https://www.discuss.wmie.uz.zgora.pl/ps/source/publish/view_pdf.php?doi=10.7151/dmps.1147" target="_blank">« Signatura of magic and Latin integer squares: isentropic clans and indexing »</a></i>, a paper which he co-authored with <a href="https://www.researchgate.net/profile/Ian-Cameron-3" target="_blank">Ian Cameron</a> and <a href="https://www.researchgate.net/scientific-contributions/Adam-Rogers-2079123350" target="_blank">Adam Rogers</a> in 2012.</p>
<p style="text-align: justify;"><i>« Signatura of magic and Latin integer squares: isentropic clans and indexing »</i> is a paper based on a video presentation in celebration of <a href="https://bibliotekanauki.pl/articles/729852.pdf" target="_blank">George Styan’s 75th</a>, (at a conference held on the 19th July, 2012 at Będlewo, Poland), and was published in <i>“Discussiones Mathematicae Probability and Statistics”</i>, Volume 33, No 1-2, pages 121-149, in 2013. The paper can be obtained via a direct download link at: <a href="https://www.discuss.wmie.uz.zgora.pl/ps/source/publish/view_pdf.php?doi=10.7151/dmps.1147">https://www.discuss.wmie.uz.zgora.pl/ps/source/publish/view_pdf.php?doi=10.7151/dmps.1147</a>.</p>
<p style="text-align: justify;">Following studies of the Shannon entropies of order-9 Sudoku and Latin square matrices by Newton and DeSalvo (<a href="https://link.springer.com/search?dc.creator=Paul+K.+Newton" target="_blank">P.K. Newton</a> and <a href="https://www.researchgate.net/profile/Stephen-Desalvo" target="_blank">S.A. DeSalvo</a>, <i><a href="https://www.jstor.org/stable/25706326" target="_blank">“The Shannon entropy of Sudoku matrices”</a></i>, Proc. R. Soc. A 466 (2010), 1957–1975.), Cameron, Rogers and Loly calculate for magic squares in their paper: <i>“a percentage of compression factor for the reduction of the entropy from a reference maximum entropy which goes as the logarithm of the order of the squares, ln(n), in order to provide a comparison across different orders. NDS found average compressions in the range of 21 to 25%.”</i></p>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5irA-Mwf2xVQu855nPgm3ck8n9uDB1nv8Nd4hTESWhmElLYZEfJowErphG-YGVmMRGDgm2l94fSBmYdI1_NzvYM69r3IyHkrtRfyX4Zi1IVNCkhGs7kBmkwwyW4yO8k921n7B6rjUVhngVBhrde0eGA1H7WQub3vivInaNHJB0fXFX0UHZ-gwYDzAgsw/s347/Durer_order-4_magic_torus.png" style="margin-left: auto; margin-right: auto;"><img alt="The famous "Dürer" magic square of order-4 can be found in the engraving "Melendolia I". It displays the 1514 date of the engraving." border="0" data-original-height="319" data-original-width="347" height="100" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5irA-Mwf2xVQu855nPgm3ck8n9uDB1nv8Nd4hTESWhmElLYZEfJowErphG-YGVmMRGDgm2l94fSBmYdI1_NzvYM69r3IyHkrtRfyX4Zi1IVNCkhGs7kBmkwwyW4yO8k921n7B6rjUVhngVBhrde0eGA1H7WQub3vivInaNHJB0fXFX0UHZ-gwYDzAgsw/s320/Durer_order-4_magic_torus.png" width="100" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The magic square of order-4 in Dürer's engraving "Melencolia I"</span><br /></td></tr></tbody></table>
<p style="text-align: justify;">
Illustrated above, the magic square of order-4, from Dürer’s famous 1514 engraving <i>“Melencolia I”</i>, has the Frénicle index 175. It is hosted in clan α of Cameron, Rogers and Loly’s Table 1, in which the authors give the following percentage of compression factor:<br />C= 37. 23% (the highest compression of Group G1-3(α) that hosts the ancient Jupiter magic square, Dürer’s famous 1514 square, as well as one of Franklin’s magic squares).</p>
<p style="text-align: justify;">
Based on the “Durer” semi-pandiagonal magic square of order-4, the “Michelet” pan zigzag magic square of order-8 is as below:</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPofiwv9hsIoRAnn_T8fQy3pXGS-8f1fFJMLxX07mb7xLYfii1cyiJFB8em19akhmrgBefeRWFqdimW8pmv08NU0NfgqRfDOpsu9bvnNBhsIQF-bo4WykQWVofssqOvaFRFfbDxsCfT8eY9tHZSLBKZDiL0JSJTedeprULfykHv8zWPg7KERi1sy23kJk/s675/Durer_order-8_PKMZZ_magic_torus.png" style="margin-left: auto; margin-right: auto;"><img alt="The "Michelet" pan-zigzag magic square of order-8 "magnifies" Dürer's magic square of order-4." border="0" data-original-height="614" data-original-width="675" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPofiwv9hsIoRAnn_T8fQy3pXGS-8f1fFJMLxX07mb7xLYfii1cyiJFB8em19akhmrgBefeRWFqdimW8pmv08NU0NfgqRfDOpsu9bvnNBhsIQF-bo4WykQWVofssqOvaFRFfbDxsCfT8eY9tHZSLBKZDiL0JSJTedeprULfykHv8zWPg7KERi1sy23kJk/w200-h200/Durer_order-8_PKMZZ_magic_torus.png" title="The "Michelet" order-8 pan-zigzag magic torus of order-8, a direct descendant of the "Dürer" magic square of order-4" width="200" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The "Michelet" order-8 pan-zigzag magic torus of order-8,<br />a direct descendant of the "Dürer" magic square of order-4</span></td><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;"><br /></span></td><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;"><br /></span></td><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;"><br /></span></td><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;"><br /></span></td><td class="tr-caption" style="text-align: center;"><br /></td></tr></tbody></table>
<p style="text-align: justify;">Peter Loly’s calculations show the following:
<br /></p><p style="text-align: left;">
singular values: [260.0, 143.15, 35.777, 8.1950, 0, 0, 0, 0],
<br />
eigenvalues: 260, 0, -64, 64
<br />
Σ_{i}ⁿσ_{i} = 260 + 143.15 + 35.777 +8.1950 = 447.12
<br />
σ₁ = 260 / 447.12 = 0.58150
<br />
σ₂ = 143.15 / 447.12 = 0.32016
<br />
σ₃ = 35.777 / 447.12 = 8.0017 × 10⁻²
<br />
σ₄ = 8.1950 / 447.12 = 1.8328 × 10⁻²
<br />
H = -σ₁ln(σ₁) -σ₁₂ln(σ₂) -σ₃ln(σ₃) -σ₄ln(σ₄)
<br />
H = -0.58150ln(0.58150) -0.32016ln(0.32016) -8.0017×10⁻²ln(8.0017×10⁻²) -1.8328×10⁻²ln(1.8328×10⁻²) = (-1.0σ₁lnσ₁-1.0σ₃lnσ₃-1.0σ₄lnσ₄-1.0σ₁₂lnσ₂ = H) = 0.95528
<br />
C=(1-(H/(ln(n))))∗100%.</p>
<p style="text-align: justify;">The resulting percentage of compression factor of the “Michelet” pan zigzag magic square of order-8 is therefore as follows:</p>
<p style="text-align: left;">
C = (1-0.95528/ln(4)) ∗ 100 = 31.091%</p>
<p style="text-align: justify;">
This can now be compared with Peter Loly’s calculation of the percentage of compression factor of the “Dürer” semi-pandiagonal square:</p>
<p style="text-align: left;">
singular values: [34.0,17. 889,4. 4721,6. 0749×10⁻³⁸],
<br />
eigenvalues: -8,0,8,34,
<br />
{{16, 3, 2, 13}, {5, 10, 11, 8}, {9, 6, 7, 12}, {4, 15, 14, 1}}
<br />
34.00 + 17.889 + 4.4721 = 56.361
<br />
σ₁ = 34 / 56.361 = 0.60325
<br />
σ₂ = 17.889 / 56.361 = 0.3174
<br />
σ3= 4.4721 / 56.361 = 7.9347 × 10⁻²
<br />
H = -0.60325ln( 0.60325) -0.3174ln(0.3174) -7.9347×10⁻²ln(7. 9347×10⁻²) = 0.8702
<br />
C = (1-0.8702/ln(4)) ∗ 100 = 37.228%
</p>
<p style="text-align: justify;">
The 37.228% percentage of compression factor C of the “Dürer” semi-pandiagonal square can be seen to be totally consistent with the 37.23% highest percentage compression factor of Group G1-3(α), as previously announced in Table 1 of the paper co-authored by Ian Cameron, Adam Rogers and Peter Loly in 2012:<i> « Signatura of magic and Latin integer squares: isentropic clans and indexing »</i>.</p>
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<div class="separator" style="clear: both; text-align: center;">
<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>
William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-33126668200232643002019-04-25T16:23:00.003+02:002023-06-19T23:01:03.704+02:00Sequenced Concentric Rings on Magic Squares or Magic Tori<div style="text-align: justify;">It is well known that sequenced concentric rings are present on classic <a href="http://mathworld.wolfram.com/BorderSquare.html" rel="" target="_blank">bordered magic squares</a> or tori. The subject of bordered magic squares is already well documented, and links for further reading are suggested at the end of this post. </div>
<br />
<div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5gH7MLhJVZhz3aInSeo1XQseoHGIkEuqTvT73fhNTDLEli3t0W-eZLj7gMt28B0CvHZgNWfb9bhAMw0zgK-qWuATvO31pGrGrXLsxsQKd1P5kWY2BtghB1gRriB7J3JbyI-6WjvPA2KM/s1600/geometric_sequenced_rings_on_magic_square_og.png" style="margin-left: auto; margin-right: auto;"><img alt="This order-5 magic square has geometric sequenced ring totals of 25, 75, and 225." border="0" data-original-height="777" data-original-width="1483" height="133" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5gH7MLhJVZhz3aInSeo1XQseoHGIkEuqTvT73fhNTDLEli3t0W-eZLj7gMt28B0CvHZgNWfb9bhAMw0zgK-qWuATvO31pGrGrXLsxsQKd1P5kWY2BtghB1gRriB7J3JbyI-6WjvPA2KM/s320/geometric_sequenced_rings_on_magic_square_og.png" title="" width="240" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Geometric sequenced ring totals (25, 75, 225) on a 5x5 magic square</span></td></tr>
</tbody></table>
</div>
<br />
<div style="text-align: justify;">However, this study is about <i>sequenced concentric rings in general</i>, and not about bordered magic squares in particular. Sequenced concentric rings exist on many different types of magic squares or magic tori, and various cases are explored up to order-10 together with one order-18 example.</div>
<div style="text-align: justify;"><br /></div>
<div style="text-align: justify;">It will be seen that the classic linear arithmetic sequences of bordered magic squares can also be found on non-bordered magic squares or tori. Also, some alternative arithmetic sequences, <i>and a geometric sequence</i>, are brought to light using simple algebra equations, and examples of each are given in the <a href="https://drive.google.com/file/d/101246dGtRaZ0rM7t2l5FTYefn-YZfLtU/view?usp=sharing" rel="" target="_blank">following document:</a></div><br />
<iframe height="373" src="https://drive.google.com/file/d/101246dGtRaZ0rM7t2l5FTYefn-YZfLtU/preview" width="518"></iframe><br />
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<h3><u>Further Reading on Bordered Magic Squares</u></h3><div style="text-align: justify;"><br />
<div style="text-align: justify;">For those amongst you who may wish to know more about the particular cases of bordered magic squares, the sites of <a href="http://www.budshaw.ca/BorderedMagicSquares.html" rel="" target="_blank">Harry White</a> and <a href="https://inderjtaneja.com/2019/03/22/embedded-magic-squares-of-consecutive-numbers-order-21x21/" rel="" target="_blank">Inder Taneja</a> contain further information and examples.</div></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Also, one of the earliest books on the subject of bordered magic squares is Bernard Violle's <a href="https://books.google.fr/books?id=NpU5AAAAcAAJ&printsec=frontcover&hl=fr#v=onepage&q&f=false" rel="" target="_blank"><i>"Traité complet des carrés magiques pairs et impairs, simples et composés, à bordures, compartiments, croix, chassis, équerres, bandes détachées etc, suivi d'un traité des cubes magiques, et d'un essai sur les cercles magiques : avec atlas de 51 grandes feuilles, comprenant 400 figures"</i></a>, which was first published in 1837. From page 44 to 213, its step-by-step diagrams, that explain how to construct bordered magic squares, can be easily understood by non-French readers.</div>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-74953854488254578982019-02-06T16:04:00.003+01:002023-06-19T23:02:51.686+02:00Smart Filling<div style="text-align: justify;">
I wish to thank <a href="http://www.gaspalou.fr/magic-squares/" rel="" target="_blank">Francis Gaspalou</a> for bringing to my attention a board game question n° J113 <i>"Savant Remplissage (1er épisode)"</i> that was asked on the site of <a href="http://www.diophante.fr/problemes-par-themes/jeux-de-plateaux/4262-j113-savant-remplissage" rel="" target="_blank">Diophante</a>:</div>
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In French, the question reads as follows:</div>
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<i>"Prouver qu'il est possible de remplir les 81 cases d' un tableau 9 x 9 avec les entiers de 1 à 81 de sorte que les sommes des nombres contenus dans tous les carrés 3 x 3 sont identiques.</i></div>
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<i>Pour les plus courageux: même question pour le remplissage des 256 cases d'.un tableau 16 x 16 avec les entiers de 1 à 256 et les sommes identiques des nombres contenus dans tous les carrés 4 x 4."</i></div>
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Translated into English, the question is as follows:</div>
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<i>Show that it is possible to fill the 81 cells of a 9 x 9 grid with the whole numbers from 1 to 81 so that the sums of the numbers contained in each of the 3 x 3 squares are identical. For the more courageous: Show that it is possible to fill the 256 cells of a 16 x 16 grid with the whole numbers from 1 to 256 so that the sums of the numbers contained in each of the 4 x 4 squares are identical.</i></div>
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The Reply to the Question</h3>
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Remembering earlier research carried out in 2016 when preparing <a href="https://carresmagiques.blogspot.com/2020/04/magic-torus-coordinate-and-vector.html" target="_blank">"Magic Torus Coordinate and Vector Symmetries"</a> I realised that the question could be answered using this modular coordinate equation:</div>
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<a href="https://blogger.googleusercontent.com/img/a/AVvXsEhriB5Z_UymtZSZnUMzZIj2h-urr2-d60qgsgnNqoM5R5eDgPilgbSKTooVD3jV8ntahulW-qgbOXkcBB6NxhVZeeEpWvvjXtkN73FUc-NQ3IM_xBtspQVsIoeBPyu8H3gw0FAANpXQX546iY8cklKUnQgSZZOX4-xODKwSggyYm_JvS4yJRj06F54a=s2772" style="margin-left: 1em; margin-right: 1em;"><img alt="A Modular Coordinate Equation for Perfect Square Order Pandiagonal Magic Tori or Magic Squares" border="0" data-original-height="1446" data-original-width="2772" height="209" src="https://blogger.googleusercontent.com/img/a/AVvXsEhriB5Z_UymtZSZnUMzZIj2h-urr2-d60qgsgnNqoM5R5eDgPilgbSKTooVD3jV8ntahulW-qgbOXkcBB6NxhVZeeEpWvvjXtkN73FUc-NQ3IM_xBtspQVsIoeBPyu8H3gw0FAANpXQX546iY8cklKUnQgSZZOX4-xODKwSggyYm_JvS4yJRj06F54a=w400-h209" width="400" /></a></div>
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The following pdf files (in <a href="https://drive.google.com/file/d/1jUaKb-hL61_FkSlLTFctzw46VZ_fErFR/view?usp=sharing" rel="" target="_blank">English</a> and <a href="https://drive.google.com/file/d/1R6-dtpd_081-PrtOQqKBnyBMJBeVkatv/view?usp=sharing" rel="" target="_blank">French</a> versions) show how the equation is used to produce <i>perfect square order N</i> pandiagonal tori that are always entirely covered by <i>N² x [√N x √N]</i> submagic squares:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiui1N_I3dYZMHjaBSd3qB3Lh7sOMFxNCmtgRNHdtQKmJPuuOVgsR9nv5LqEIZ-eKGapvswbcNfF8_fEyoLITkwAWky37YR4PmZ9K9YnGYjMfdd0I8rl33wa3Lg-5WxznFTrE53A_mnpOg/s1600/united-kingdom-gb-flag-icon-32.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="32" data-original-width="32" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiui1N_I3dYZMHjaBSd3qB3Lh7sOMFxNCmtgRNHdtQKmJPuuOVgsR9nv5LqEIZ-eKGapvswbcNfF8_fEyoLITkwAWky37YR4PmZ9K9YnGYjMfdd0I8rl33wa3Lg-5WxznFTrE53A_mnpOg/s1600/united-kingdom-gb-flag-icon-32.png" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiiElkylIr1w4gJZTKbp6R11gsOl4DLNjdmzJ_dYIwHWNTVvxEROAC20Nq5ssA9gaVhlCn5YxGFHwAhoSiKqRFfTK1dyIaQ9zeCmCVpNTQmwlIlcFCxpMZtYJNmQ0EgQVOvV6YFm4YcJbI/s1600/france-flag-icon-32.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="32" data-original-width="32" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiiElkylIr1w4gJZTKbp6R11gsOl4DLNjdmzJ_dYIwHWNTVvxEROAC20Nq5ssA9gaVhlCn5YxGFHwAhoSiKqRFfTK1dyIaQ9zeCmCVpNTQmwlIlcFCxpMZtYJNmQ0EgQVOvV6YFm4YcJbI/s1600/france-flag-icon-32.png" /></a></div>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-29274732760784524782018-08-26T15:47:00.003+02:002023-06-19T23:03:27.240+02:00Magic Triangular Pyramids<h3 style="text-align: justify;">
Why Magic Triangular Pyramids and not Magic Tetrahedra?</h3>
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Because different edge lengths can only result in irregular and non-isosceles polyhedra, <i>4-faced perimeter-magic</i> tetrahedra <a href="https://drive.google.com/file/d/153xOAH6inu0bVcb9CZnLmt98i7zQMhID/view?usp=sharing" rel="" target="_blank">cannot exist</a>. Nevertheless, it is possible to construct <i>3-faced Perimeter-Magic</i> Triangular Pyramids.</div>
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Unlike a tetrahedron, whose four triangular faces can each be considered as its base, a Magic Triangular Pyramid is deemed to have a <i>single triangular base and three triangular faces</i>. The 6 connecting edges of a Magic Triangular Pyramid have different integer lengths, <i>but the 3 triangular faces have the same perimeter</i>.</div>
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Primitive Magic Triangular Pyramids using Consecutive Numbers</h3>
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Using consecutive numbers from 1 to 6 for each of the edges, we can create 4 essentially different <i>Primitive</i> Magic Triangular Pyramids:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEin93rwlmfSfF8JG4prHgE9cpYYsvziFK3RzZfrYUiuGK22Onf81ef4Vo_klcH5XIgtTWDYaK5BcJQdoAEUmBoh4HS2beEMNRJlHtGa7D-R9Yg5rQhIvcsreK-Wc6Qqk-LiSDGuslZaMD0/s1600/Primitive-Magic-Triangular-Pyramids_A-B.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Solutions A and B of 4 essentially different Primitive Magic Triangular Pyramids with consecutive numbers." border="0" data-original-height="835" data-original-width="1600" height="199" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEin93rwlmfSfF8JG4prHgE9cpYYsvziFK3RzZfrYUiuGK22Onf81ef4Vo_klcH5XIgtTWDYaK5BcJQdoAEUmBoh4HS2beEMNRJlHtGa7D-R9Yg5rQhIvcsreK-Wc6Qqk-LiSDGuslZaMD0/s320/Primitive-Magic-Triangular-Pyramids_A-B.png" title="" width="384" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhn6J1lAA8B6s-bJorFzDWDvgGXSvi1uGeFzuE0I0_j3qsEpNs5zfOy4Z8a-RMgaBl6zJIzlN_b06PQIV3PJOwsBu4QX77_F9BSHjHL2vvz_Y56v8hLPUxl6TbdP9dHGp88XqYtZvCs_U8/s1600/Primitive-Magic-Triangular-Pyramids_C-D.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Solutions C and D of 4 essentially different Primitive Magic Triangular Pyramids with consecutive numbers." border="0" data-original-height="876" data-original-width="1600" height="210" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhn6J1lAA8B6s-bJorFzDWDvgGXSvi1uGeFzuE0I0_j3qsEpNs5zfOy4Z8a-RMgaBl6zJIzlN_b06PQIV3PJOwsBu4QX77_F9BSHjHL2vvz_Y56v8hLPUxl6TbdP9dHGp88XqYtZvCs_U8/s320/Primitive-Magic-Triangular-Pyramids_C-D.png" title="" width="384" /></a></div>
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The perimeters of <b>Solution <span style="color: red;">A</span></b> are the opposite vertices of <b>Solution <span style="color: red;">D</span></b><span style="color: red;"><span style="color: black;">,</span></span> and vice versa. The same relationship exists between the <b>Solution <span style="color: red;">B</span></b> and the <b>Solution <span style="color: red;">C</span></b>.<br /><br /></div>
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Only two of the <i>primitive</i> solutions have consecutive numbers for their base and for one of their face edges. These are the <b>Solution <span style="color: red;">A</span></b><span style="color: red;"><span style="color: black;"> with base edges (1, 2, 3) and a face with edges (3, 4, 5), and the <b>Solution <span style="color: red;">D</span></b> with base edges </span></span><span style="color: red;"><span style="color: black;"><span style="color: red;"><span style="color: black;">(4, 5, 6) and a face with edges</span></span> (2, 3, 4).</span></span><br /><br /></div>
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These four <i>primitive pyramids</i> are not just abstract numerical polyhedra (which display triangles that are either impossible, or too obtuse for 3D assembly), as they can also be extrapolated to construct viable consecutive-numbered Magic Triangular Pyramids.</div>
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For example, the <i>Primitive</i> Magic Triangular Pyramid <span style="color: red;"><b><span style="color: black;">Solution</span></b> <b>A</b></span> only displays a single valid triangle which is the Pythagorean triple (3, 4, 5). The three other triangles (1, 2, 3), (1, 5, 6), and (2, 4, 6) do not exist! To obtain valid triangles we need to add 1 to each of the consecutive numbers. <i>However, this is still insufficient,</i> as some of the triangles are too obtuse and cannot be assembled correctly. To construct the <i>smallest</i> Magic Triangular Pyramid derived from <b>Solution <span style="color: red;">A</span></b>, we need to add 2 and use the consecutive numbers 3 to 8, as shown in the net diagrams below:</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEvWE42xrl53hRf-KCkSUUdUGwaQADWhJ8RP4vxqkOHCmYXLhzCb1cgsrb0HtZ6TQirD6MT1NCweuTQZUR8GkFl0XdciqMrq0ERWNIhdfGT_8hINrzeO7w4aZfI38GCQdcxFc45m9SKVU/s1600/Nets-of-Magic-Triangular-Pyramids.png" style="margin-left: 1em; margin-right: 1em;"><img alt="These nets show how the smallest Magic Trangular Pyramid is constructed." border="0" data-original-height="1600" data-original-width="742" height="595" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEvWE42xrl53hRf-KCkSUUdUGwaQADWhJ8RP4vxqkOHCmYXLhzCb1cgsrb0HtZ6TQirD6MT1NCweuTQZUR8GkFl0XdciqMrq0ERWNIhdfGT_8hINrzeO7w4aZfI38GCQdcxFc45m9SKVU/s640/Nets-of-Magic-Triangular-Pyramids.png" title="" width="275" /></a></div>
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Likewise, the <i>Primitive </i><b>Solutions <span style="color: red;">B</span></b><span style="color: red;"><span style="color: black;"> and <span style="color: red;"><b>C</b></span> can only become Magic Triangular Pyramids after adding 5, and using the consecutive numbers from 6 to 11. </span></span></div>
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<span style="color: red;"><span style="color: black;">On the other hand, for the <i>Primitive</i><b> Solution <span style="color: red;">D</span></b> to become a Magic Triangular Pyramid, it is only necessary to add 4, and use the consecutive numbers from 5 to 10.</span></span></div>
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<span style="color: red;"><span style="color: black;">Magic Triangular Pyramids using Consecutive Numbers<br />
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1/ The Smallest Magic Triangular Pyramid using Consecutive Numbers</h4>
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As shown above, the smallest Magic Triangular Pyramid that can be constructed using consecutive numbers is the <i>Primitive</i> <b>Solution <span style="color: red;">A</span> + 2</b>. The resulting pyramid, which uses the numbers 3 to 8, is illustrated below:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiAHyRhsM-rhRGm_xXoYW3APZsE-CXc0t65lQsZyXnAPxkBwWGOO-0acfz06Z_6gV3Jk1UYMtfciG57LupWiKAP4KNtpx_Tj5qeAvgIVUKOfE7Ko4nNIzEjFEq316LyiD2trbHBkC42mM4/s1600/Magic-Triangular-Pyramid-with-Pythagorean-Triangle-Base.png" style="margin-left: 1em; margin-right: 1em;"><img alt="The smallest Magic Triangular Pyramid has the primitive Pythagorean triangle (3, 4, 5) as base." border="0" data-original-height="1564" data-original-width="1600" height="312" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiAHyRhsM-rhRGm_xXoYW3APZsE-CXc0t65lQsZyXnAPxkBwWGOO-0acfz06Z_6gV3Jk1UYMtfciG57LupWiKAP4KNtpx_Tj5qeAvgIVUKOfE7Ko4nNIzEjFEq316LyiD2trbHBkC42mM4/s320/Magic-Triangular-Pyramid-with-Pythagorean-Triangle-Base.png" title="" width="320" /></a></div>
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The striking characteristic of this smallest Magic Triangular Pyramid is that it is based on the primitive Pythagorean Triangle (3, 4, 5). The volume V of a pyramid is 1/3 of the base area x the height of the apex. Therefore, in this case, as the area of the base is 6, the volume V is the height of the pyramid x 2. </div>
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<i>With non-rational numbers rounded to five or six decimal places*</i>, the other details of this Magic Triangular Pyramid are as follows:<br />
The perimeter of the triangular base is 12. </div>
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The perimeter of each of the three triangular faces is 18.<br />
The total perimeters of the triangular base and faces is 66.<br />
The area of the primitive Pythagorean triangle base (3, 4, 5) is 6. <br />
The area of the triangular face (3, 7, 8) is 10.39230...*<br />
The area of the triangular face (4, 6, 8) is 11.61895...*<br />
The area of the triangular face (5, 6, 7) is 14.69694...*<br />
The total areas of the triangular base and faces is 42.70819...*<br />
The height of the apex is 4.213075...*<br />
The volume V of the pyramid is 8.42615...*<br />
The base vertices (3, 4, 8), (4, 5, 6) and (3, 5, 7) each total 15.<br />
The apex (6, 7, 8) totals 21.</div>
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2/ The Smallest Magic Triangular Pyramid with an Integer Volume using Consecutive Numbers </h4>
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The smallest Magic Triangular Pyramid with an integer volume that can be constructed using consecutive numbers is the <i>Primitive</i><b> Solution <span style="color: red;">D</span> + 5</b>. The resulting pyramid, which uses the numbers 6 to 11, is illustrated below:</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEir18Kc1jbFjJtBkacUbJDYVSutfxDHiuR27nFqQ0R4xkGhtdH44urjl07u87xP4p_V2uKYIn8FeY4OY5-w3wvDZBFl1KJ97RQv6HiBdvmgYK7LCEkBhiECmPLp_loUR7yZuO9_s2RJ9Ao/s1600/Magic-Triangular-Pyramid-with-integer-volume.png" style="margin-left: 1em; margin-right: 1em;"><img alt="This is the smallest Magic Triangular Pyramid with an integer volume." border="0" data-original-height="1218" data-original-width="1600" height="303" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEir18Kc1jbFjJtBkacUbJDYVSutfxDHiuR27nFqQ0R4xkGhtdH44urjl07u87xP4p_V2uKYIn8FeY4OY5-w3wvDZBFl1KJ97RQv6HiBdvmgYK7LCEkBhiECmPLp_loUR7yZuO9_s2RJ9Ao/s400/Magic-Triangular-Pyramid-with-integer-volume.png" title="" width="400" /></a></div>
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The main characteristics of this Magic Triangular Pyramid is that it not only has a non-primitive Pythagorean triangle face (with area and perimeter both equal to 24), but also an integer volume of 48.</div>
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<i>With non-rational numbers rounded to five or six decimal places*</i>, the other details of this Magic Triangular Pyramid are as follows:</div>
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The perimeter of the triangular base is 30.</div>
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The perimeter of each of the three triangular faces is 24.</div>
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The total perimeters of the triangular base and faces is 102.</div>
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The area of the triangular base (9, 10, 11) is 42.42641...*</div>
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The area of the non-primitive Pythagorean triangle face (6, 8, 10) is 24.</div>
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The area of the triangular face (7, 8, 9) is 26.83282...*</div>
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The area of the triangular face (6, 7, 11) is 18.97367...*</div>
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The total areas of the triangular base and faces is 112.23289...*</div>
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The height of the apex is 3.39411...*</div>
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The volume V of the pyramid is 48.<br />
The perpendicular distance from the Pythagorean triangle face (6, 8, 10) to the opposite vertex (7, 9, 11) is 3 x 48 / 24 = 6.<br />
The base vertices (8, 9, 10), (6, 10, 11) and (7, 9, 11) each total 27.<br />
The apex (6, 7, 8) totals 21.</div>
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<br /></div>
<div style="text-align: justify;">
This integer volume tetrahedron has already been described elsewhere, (for example in C. Chisholm and J.A. MacDougall's paper <a href="https://core.ac.uk/download/pdf/82117537.pdf" rel="" target="_blank">"Rational tetrahedra with edges in arithmetic progression"</a> and in Wikipedia's article <a href="https://en.wikipedia.org/wiki/Tetrahedron#Integer_tetrahedra" rel="" target="_blank">"Tetrahedron"</a>), but no previous mention seems to have been made of the equal perimeter faces and the resulting magic pyramid aspect. C. Chisholm and J.A. MacDougall conjecture that <i>"this is the only tetrahedron with edges in arithmetic progression having rational volume and a rational face area."</i><br />
<br />
<h3>
Magic Triangular Pyramids using Non-Consecutive Numbers</h3>
<h4>
<br />
1/ A Magic Triangular Pyramid with 2 Primitive Pythagorean Triangles</h4>
<br />
The following Magic Triangular Pyramid has been constructed using two primitive Pythagorean triangles. The Pythagorean triangle used for the base (3, 4, 5) is the same as that used for the smallest Magic Triangular Pyramid (see <b>Solution <span style="color: red;">A</span> + 2</b>). The result is illustrated below:<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhThJNkRzEB45oxGNSwr15FrWsuPATYTegtjGRVh9QGPgnZsVOYubH-jKhivXEsIX_cGa3TjZ4H3YuQ7LFZwe27I5BD5oWcX_v-vtnFny0HFpS8AA3Dfrc6R6VojngBF7OnGnyfX4peWN8/s1600/Magic-Triangular-Pyramid-2-primitive-Pythagorean-triangles.png" style="margin-left: 1em; margin-right: 1em;"><img alt="This is a Magic Triangular Pyramid with 2 primitive Pythagorean triangles." border="0" data-original-height="1600" data-original-width="1255" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhThJNkRzEB45oxGNSwr15FrWsuPATYTegtjGRVh9QGPgnZsVOYubH-jKhivXEsIX_cGa3TjZ4H3YuQ7LFZwe27I5BD5oWcX_v-vtnFny0HFpS8AA3Dfrc6R6VojngBF7OnGnyfX4peWN8/s400/Magic-Triangular-Pyramid-2-primitive-Pythagorean-triangles.png" title="" width="313" /></a></div>
<br />
The main characteristic of this Magic Triangular Pyramid is that the Pythagorean triangle (5, 12, 13) aligns the face edge 12 at right angles to the base edge 5. Also, as in the example of the smallest Magic Triangular Pyramid (see above), the volume is twice the height of the apex. We can see that this pyramid is equivalent to the <i>Primitive</i> <b>Solution <span style="color: red;">A</span> + 8</b> for the 3 numbers that are greater than 3, and equivalent to the <i>Primitive</i> <b>Solution <span style="color: red;">A</span> + 2</b> for the 3 numbers that are less than 4.<br />
<br />
<span style="font-weight: normal;"><i>With non-rational numbers rounded to five or six decimal places*</i>, the other details of this Magic Triangular Pyramid are as follows:</span><br />
<span style="font-weight: normal;">The perimeter of the triangular base is 12.</span><br />
<span style="font-weight: normal;">The perimeter of each of the three triangular faces is 30.</span><br />
The total perimeters of the triangular base and faces is 102.<br />
The area of the primitive Pythagorean triangular base (3, 4, 5) is 6.<br />
The area of the primitive Pythagorean triangular face (5, 12, 13) is 30.<br />
The area of the triangular face (3, 13, 14) is 18.97367...*<br />
The area of the triangular face (4, 12, 14) is 22.24859...*<br />
The total areas of the triangular base and faces is 77.22226...*<br />
The height of the apex is 9.367497...*<br />
The volume V of the pyramid is 18.734994...*<br />
The base vertices (3, 5, 13), (4, 5, 12) and (3, 4, 14) each total 21.<br />
The apex (12, 13, 14) totals 39.<br />
<br />
<h4>
2/ A Magic Triangular Pyramid with 2 Non-Primitive Pythagorean Triangle Faces</h4>
<br />
<span style="font-weight: normal;">The following Magic Triangular Pyramid has been constructed using two non-primitive Pythagorean triangles that both have the same perimeter of 420, and share a same side length of 175. The resulting pyramid is illustrated below.</span><br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgYIDtjMlLMNHwTUiJvAQJRxQclFA1hbYnDJLeHEXbXA-vpJdB4PH1O_u1NmBoZY5m7RXIkT54JuHHD0pFjuKsrB_Hl26FGbgTYMufZmM2bU0NCenTOvlM7xghlBH1VU0mNHYes_2Mtx48/s1600/Magic-Triangular-Pyramid-with-2-Pythagorean-triangles.png" style="margin-left: 1em; margin-right: 1em;"><img alt="This is a Magic Triangular Pyramid with 2 non-primitive Pythagorean triangles." border="0" data-original-height="1412" data-original-width="1600" height="352" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgYIDtjMlLMNHwTUiJvAQJRxQclFA1hbYnDJLeHEXbXA-vpJdB4PH1O_u1NmBoZY5m7RXIkT54JuHHD0pFjuKsrB_Hl26FGbgTYMufZmM2bU0NCenTOvlM7xghlBH1VU0mNHYes_2Mtx48/s400/Magic-Triangular-Pyramid-with-2-Pythagorean-triangles.png" title="" width="400" /></a></div>
<br />
<span style="font-weight: normal;">The main characteristic of this Magic Triangular Pyramid is that the Pythagorean triangles align the face edges 175 and 140 at right angles to the base edges 60 and 105.</span><br />
<br />
<span style="font-weight: normal;"><i>With non-rational numbers rounded to five or six decimal places*</i>, the other details of this Magic Triangular Pyramid are as follows:</span><br />
<span style="font-weight: normal;">The perimeter of the triangular base is 260.</span><br />
<span style="font-weight: normal;">The perimeter of each of the three triangular faces is 420.</span><br />
The total perimeters of the triangular base and faces is 1520.<br />
The area of the triangular base (60, 95, 105) is 2821.79021...*<br />
The area of the non-primitive Pythagorean triangular face (105, 140, 175) is 7350.<br />
The area of the non-primitive Pythagorean triangular face (60, 175, 185) is 5250.<br />
The area of the triangular face (95, 140, 185) is 6500.96147...*<br />
The total areas of the triangular base and faces is 21922.75168...*<br />
The height of the apex is 129.94673...*<br />
The volume V of the pyramid is 122227.474635...*<br />
The base vertices (60, 95, 185), (95, 105, 140) and (60, 105, 175) each total 340.<br />
The apex (140, 175, 185) totals 500.<br />
<br />
<h4>
3/ A Degenerate Heronian Magic Triangular Pyramid with Zero Volume</h4>
<br />
For the definition of a Heronian Magic Triangular Pyramid, we can refer to the description of a <a href="http://mathworld.wolfram.com/HeronianTetrahedron.html" rel="" target="_blank">Heronian Tetrahedron</a> (or Perfect Tetrahedron) as detailed by Eric Weisstein in MathWorld:<i> <br />
"A Heronian tetrahedron, also called a perfect tetrahedron, is a (not necessarily regular) <a href="http://mathworld.wolfram.com/Tetrahedron.html" rel="" target="_blank">tetrahedron</a> whose sides, <a href="http://mathworld.wolfram.com/Face.html" rel="" target="_blank">face</a> <a href="http://mathworld.wolfram.com/Area.html" rel="" target="_blank">areas</a>, and <a href="http://mathworld.wolfram.com/Volume.html" rel="" target="_blank">volume</a> are all <a href="http://mathworld.wolfram.com/RationalNumber.html" rel="" target="_blank">rational numbers</a>. It therefore is a <a href="http://mathworld.wolfram.com/Tetrahedron.html" rel="" target="_blank">tetrahedron</a> all of whose faces are <a href="http://mathworld.wolfram.com/HeronianTriangle.html" rel="" target="_blank">Heronian triangles</a> and additionally that has rational volume.</i>" <br />
We will impose two further constraints:<i> <br />
The 6 integer edge lengths must be different (with no <a href="http://mathworld.wolfram.com/IsoscelesTriangle.html" rel="" target="_blank">isosceles triangles</a>). The perimeters of 3 out of the 4 faces must be equal.</i></div>
<div style="text-align: justify;">
<br />
This <a href="https://en.wikipedia.org/wiki/Degeneracy_%28mathematics%29#Convex_polyhedron" rel="" target="_blank">degenerate</a> Heronian Magic Triangular Pyramid was found when searching for a solution using <a href="http://mathworld.wolfram.com/HeronianTriangle.html" rel="" target="_blank">Heronian triangles</a>. The Pyramid can be correctly assembled, but the resulting apex has zero altitude! The following net diagram shows the plan view of the components of the pyramid together with the construction lines for the apex intersection, prior to assembly:<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEho3htQSTXeAlImCVAYhTAWUOGfgI-YKQnefpGBL0Zx-1j_ZbMQ5QdMQDTGFgQRETczPHL9On9mlQiazXfQjNkP6hsyphLEQRQYFgRthFOYZ3k5-TXN1P1jhL8RfzahHx_03svk2BYuqf0/s1600/Net-Degenerate-Heronian-Magic-Triangular-Pyramid.png" style="margin-left: 1em; margin-right: 1em;"><img alt="This net shows a degenerate Heronian Magic Triangular Pyramid prior to assembly. The resulting volume is a rational number - but zero.al" border="0" data-original-height="1245" data-original-width="1600" height="311" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEho3htQSTXeAlImCVAYhTAWUOGfgI-YKQnefpGBL0Zx-1j_ZbMQ5QdMQDTGFgQRETczPHL9On9mlQiazXfQjNkP6hsyphLEQRQYFgRthFOYZ3k5-TXN1P1jhL8RfzahHx_03svk2BYuqf0/s400/Net-Degenerate-Heronian-Magic-Triangular-Pyramid.png" title="" width="400" /></a></div>
<br />
The 3D view that follows shows the degenerate Heronian Magic Triangular Pyramid after it is assembled. Although the faces (10, 35, 39) and (17, 28, 39) can fold over the base, the third face (21, 35, 28) has to remain in a horizontal position - thereby imposing the coplanarity of the four vertices:<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi50IASdeF1MoFGxgrcI1x2aCxHNg1EZySEdqToImrZcMR1pufRt1FYUnLiOREF2KToIc0f97DPADRy6EU0qocjSRxOZB5J5AisucHY0yggoyZf_c9RGqmHxXQH0VIhTpoCmUjvSkbeUaA/s1600/Degenerate-Heronian-Magic-Triangular-Pyramid.png" style="margin-left: 1em; margin-right: 1em;"><img alt="This is a 3D view of a degenerate Heronian Magic Triangular Pyramid with zero volume." border="0" data-original-height="1059" data-original-width="1600" height="263" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi50IASdeF1MoFGxgrcI1x2aCxHNg1EZySEdqToImrZcMR1pufRt1FYUnLiOREF2KToIc0f97DPADRy6EU0qocjSRxOZB5J5AisucHY0yggoyZf_c9RGqmHxXQH0VIhTpoCmUjvSkbeUaA/s400/Degenerate-Heronian-Magic-Triangular-Pyramid.png" title="" width="400" /></a></div>
<br />
<div class="separator" style="clear: both; text-align: center;">
</div>
The example is particularly interesting because Heronian triangles are used throughout the construction, <i>and this produces totally rational areas and volume</i>, (albeit zero for the latter).<br />
<br />
The details of this degenerate Heronian Magic Triangular Pyramid are as follows:<br />
<span style="font-weight: normal;">The perimeter of the Heronian triangular base is 48.</span><br />
<span style="font-weight: normal;">The perimeter of each of the three Heronian triangular faces is 84.</span><br />
The total perimeters of the Heronian triangular base and faces is 300.<br />
The area of the primitive Heronian triangular base (10, 17, 21) is 84.<br />
The area of the Heronian <i>and non-primitive Pythagorean</i> triangular face (21, 28, 35) is 294.<br />
The area of the primitive Heronian triangular face (10, 35, 39) is 168.<br />
The area of the primitive Heronian triangular face (17, 28, 35) is 210.<br />
The total areas of the triangular base and faces is 756.<br />
The height of the apex is 0.<br />
The volume V of the pyramid is 0.<br />
The base vertices (10, 21, 35), (10, 17, 39) and (17, 21, 28) each total 66.<br />
The apex (28, 35, 39) totals 102.<br />
<br />
Degenerate examples, (with a volume, that<i> although rational</i>, is equal to zero),<i> </i>should not be neglected: Their perfect geometry makes them worthy of interest.<i> </i>Both Heronian and degenerate Heronian<i> </i>Magic Triangular Pyramids merit to become the subject of future research.<br />
<br />
<h4>
4/ An Integer Heronian Magic Triangular Pyramid</h4>
<br />
On the 26th August 2018, a first Heronian Magic Triangular Pyramid was jointly discovered by <a href="http://www.trump.de/magic-squares/" rel="" target="_blank">Walter Trump</a> and <a href="https://carresmagiques.blogspot.com/" target="_blank">William Walkington</a>. This example was found in a list of Heronian Tetrahedra that had previously been calculated by <a href="https://www.researchgate.net/profile/Sascha_Kurz" rel="" target="_blank">Sascha Kurz</a> during his research <a href="http://sci-gems.math.bas.bg/jspui/bitstream/10525/382/1/sjc058-vol2-num2-2008.pdf" rel="" target="_blank">"On the Generation of Heronian Triangles."</a> (At the time, Sascha Kurz was not looking for solutions with 3 equal face perimeters).<br />
<br />
The net of this Integer Heronian Magic Triangular Pyramid is shown below:<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh7OpFTacMOIZVTrAGnFHTvRdK9431MUGrxOhehJSbDa38VUiKkAqgWYfkTBWlrejgW3s5vpYBdYHBMg4VmRx_WtI6gmeTKupBccUSj7F_-js0xQkTxBhHzGNEmwoM78TTArEn7qh_3aYc/s1600/Net-Heronian-Magic-Triangular-Pyramid.png" style="margin-left: 1em; margin-right: 1em;"><img alt="This is a net of the first Integer Heronian Magic Triangular Pyramid." border="0" data-original-height="1600" data-original-width="1469" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh7OpFTacMOIZVTrAGnFHTvRdK9431MUGrxOhehJSbDa38VUiKkAqgWYfkTBWlrejgW3s5vpYBdYHBMg4VmRx_WtI6gmeTKupBccUSj7F_-js0xQkTxBhHzGNEmwoM78TTArEn7qh_3aYc/s400/Net-Heronian-Magic-Triangular-Pyramid.png" title="" width="366" /></a></div>
<br />
The 3D view that follows shows the Integer Heronian Magic Triangular Pyramid after it is assembled:<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbDRxz3Hy0IBsKLBhoELaqfbqGPGG87ZmOoO8nYqPK2uVt3F1OQ6_SUZSY8ie1Qu977cvTQwava-kLbUAQ1VaEU0SCNKYOlX_vNP4Dc6YWXcTxRHa4P02UCNxNj0v9Nagv8qmAmMO9XBQ/s1600/Heronian-Magic-Triangular-Pyramid.png" style="margin-left: 1em; margin-right: 1em;"><img alt="This is a 3D view of the first Integer Heronian Magic Triangular Pyramid." border="0" data-original-height="1258" data-original-width="1600" height="312" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbDRxz3Hy0IBsKLBhoELaqfbqGPGG87ZmOoO8nYqPK2uVt3F1OQ6_SUZSY8ie1Qu977cvTQwava-kLbUAQ1VaEU0SCNKYOlX_vNP4Dc6YWXcTxRHa4P02UCNxNj0v9Nagv8qmAmMO9XBQ/s400/Heronian-Magic-Triangular-Pyramid.png" title="" width="400" /></a></div>
<br />
The example is particularly interesting because Heronian triangles are used throughout the construction, and in this case, <i>totally rational integer areas and volume are produced.</i><br />
<br />
The details of this Integer Heronian Magic Triangular Pyramid are as follows:<br />
The perimeter of the primitive Heronian triangular base W is 2587706.<br />
The perimeter of each of the three Heronian triangular faces is 2004956.<br />
The total perimeters of the Heronian triangular base and faces is 8602574.<br />
The area of the primitive Heronian triangular base W (773053, 860349, 954304) is 314938488480.<br />
The area of the Heronian triangular face X (569974, 662929, 773053) is 183994812120.<br />
The area of the primitive Heronian triangular face Y (481678, 662929, 860349) is 158732366520.<br />
The area of the Heronian triangular face Z (481678, 568974, 954304) is 104418108480.<br />
The total areas of the Heronian triangular base and faces is 762083775600.<br />
The non-integer, but rational height of the apex is 214201+83/85.<br />
The volume V of the pyramid is 22486815566358528.<br />
The base vertices (662929, 773053, 860349), (481678, 860349, 954304) and (568974, 773053, 954304) each total 2296331.<br />
The apex (481678, 568974, 662929) totals 1713581.<br />
<br />
<h4>
5/ A Prime Perimeter Magic Triangular Pyramid</h4>
<span style="font-weight: normal;"><br />
Two months after the first publication of this post, the following Magic Triangular Pyramid was constructed using <i>prime number</i> perimeters: </span><br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEip8iVbZTkkISf3CtP7NmEKul-yLD4Pjz8iqKuz6ZuKpQJMBV0jxwX8iFyJJcQ1ZAidEejmKkbHAvU8KHiAijjzhNN8SDMTs81GdW-VpyOCnYy6j6VtH-dPnwXOcdp4SISiqU8eKckpBdQ/s1600/Prime-Magic-Triangular-Pyramid.png" style="margin-left: 1em; margin-right: 1em;"><img alt="A Magic Triangular Pyramid with Prime Number Perimeters." border="0" data-original-height="1600" data-original-width="1536" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEip8iVbZTkkISf3CtP7NmEKul-yLD4Pjz8iqKuz6ZuKpQJMBV0jxwX8iFyJJcQ1ZAidEejmKkbHAvU8KHiAijjzhNN8SDMTs81GdW-VpyOCnYy6j6VtH-dPnwXOcdp4SISiqU8eKckpBdQ/s320/Prime-Magic-Triangular-Pyramid.png" title="" width="307" /></a></div>
<br />
<i>With non-rational numbers rounded to five or six decimal places*</i>, the details of this Prime Perimeter Magic Triangular Pyramid are as follows: <br />
The perimeter of the triangular base is 47.<br />
The perimeter of each of the three triangular faces is 71.<br />
The total of the perimeters of the triangular base and faces is 254.<br />
The area of the triangular base (11, 17, 19) is 92.69405…*<br />
The area of the triangular face (11, 29, 31) is 159.49980…*<br />
The area of the triangular face (17, 23, 31) is 192.20351...*<br />
The area of the triangular face (19, 23, 29) is 218.15634...*<br />
The total of the areas of the triangular base and faces is 662.55370...*<br />
The height of the apex is 21.05451...*<br />
The volume V of the pyramid is 650.54247...*<br />
The base vertices (11, 17, 31), (17, 19, 23) and (11, 19, 29) each total 59.<br />
The apex (23, 29, 31) totals 83.<br />
<br />
<h3>
Acknowledgements</h3>
<br />
<div style="text-align: justify;">
<a href="https://www.grogono.com/magic/" rel="" target="_blank">Alan Grogono</a> has written an improved version of my <a href="https://drive.google.com/file/d/153xOAH6inu0bVcb9CZnLmt98i7zQMhID/view?usp=sharing" rel="" target="_blank">proof concerning the impossibility of having equal perimeters for the four faces of a tetrahedron</a> (except if the triangles are fully congruent), and I wish to thank him for this contribution.<br />
<br /></div>
<a href="http://www.trump.de/magic-squares/" rel="" target="_blank">Walter Trump</a> has kindly provided a list of <a href="https://drive.google.com/file/d/15wvXPb7Z2Fy88mVNsa4yM8hIe5Jpusz0/view?usp=sharing" rel="" target="_blank">"all Heronian non isosceles triangles up to perimeter p=10000"</a> which should prove to be an invaluable tool when searching for Heronian solutions. In addition, he has <a href="https://drive.google.com/file/d/1NvyCQu1PhNBBTwAVIEAHcvHDH7WBSrDh/view?usp=sharing" rel="" target="_blank">simplified</a> my <a href="https://drive.google.com/file/d/17Ba1OEq9-SHdAh2mbh6DOuYYPJmOWdo3/view?usp=sharing" rel="" target="_blank">initial proof</a> as to <i>why the totals of the edge lengths of each of the base vertices of a MTP are always equal</i>, and he has discovered <span style="color: red;"><span style="color: black;"><a href="https://drive.google.com/file/d/1DAjLS5IlnKbcIjuslk5H3d84QBv4_FhA/view?usp=sharing" rel="" target="_blank">another interesting property</a> of all Magic Triangular Pyramids (MTP): </span></span><br />
<div style="text-align: center;">
<div style="text-align: center;">
<span style="color: blue;"><span style="color: blue;"><span style="color: blue;"><b>a - a' = b - b' = c - c'</b></span></span></span></div>
</div>
<br />
My thanks also go to Walter Trump for his large contribution to the definition of the edge length notation schema for the Magic Triangular Pyramids, which is explained in the observations that follow.<br />
<br />
<h3>
Observations</h3>
<br />
<i>In order to facilitate any correspondence and exchanges</i> it will be useful to adopt the same way of writing the edge lengths of the Magic Triangular Pyramids. It is proposed that we always use the following schema:<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiaCpxUA_3dURqtmZ0pf9JE4VzoIDenfTm0QfEpszRcjnd_U2eoq1-Do5XpwzM8IaZt2VTxbtra9He-FvPhQXNEdbcKzgyqGs2BvDAuos_epxAZz5CZgcHk6QbO4L4e87uRs6tN084T3ME/s1600/Schema-Magic-Triangular-Pyramid.png" style="margin-left: 1em; margin-right: 1em;"><img alt="This is a useful schema for a normalised lettering and numbering of Magic Triangular Pyramids (MTP). The base edges are (a, b, c), and the apex edges are (a', b', c'). The edge lengths of a Magic Triangular Pyramid can be expressed as (a, b, c, a', b', c') where a < b < c." border="0" data-original-height="1359" data-original-width="1436" height="188" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiaCpxUA_3dURqtmZ0pf9JE4VzoIDenfTm0QfEpszRcjnd_U2eoq1-Do5XpwzM8IaZt2VTxbtra9He-FvPhQXNEdbcKzgyqGs2BvDAuos_epxAZz5CZgcHk6QbO4L4e87uRs6tN084T3ME/s200/Schema-Magic-Triangular-Pyramid.png" title="" width="200" /></a></div>
<br />
<div style="text-align: justify;">
In this case the edges (<span style="color: blue;"> <b>a</b></span>, <b><span style="color: blue;">b</span></b>, <b><span style="color: blue;">c</span></b> ) are <i>base to face edges</i>, and the edges (<span style="color: blue;"> <b>a'</b></span>, <b><span style="color: blue;">b'</span></b>, <b><span style="color: blue;">c'</span></b> ) are <i>face to face edges</i>. The letters (<span style="color: blue;"> <b>a</b></span>, <b><span style="color: blue;">a'</span></b> ), (<span style="color: blue;"> <b>b</b></span>, <span style="color: blue;"><b>b'</b> </span>), (<span style="color: blue;"> <b>c</b></span>, <b><span style="color: blue;">c'</span></b> ) <i>represent pairs of opposite edges which do not share a same vertex</i>. Without needing to illustrate the tetrahedron, the edge lengths of a Magic Triangular Pyramid can be expressed as ( <b><span style="color: blue;">a</span></b>, <b><span style="color: blue;">b</span></b>, <b><span style="color: blue;">c</span></b>, <b><span style="color: blue;">a'</span></b>, <b><span style="color: blue;">b'</span></b>, <span style="color: blue;"><b>c'</b></span> ) where <span style="color: blue;"><b>a < b < c</b><span style="color: black;">.</span></span> Taking for example, the edge lengths of some of the different cases of Magic Triangular Pyramids illustrated at the beginning, these should be conventionally expressed as follows:</div>
<div style="text-align: justify;">
The edges of the <i>Primitive</i> Magic Triangular Pyramid <b>Solution <span style="color: red;">A</span></b><span style="color: red;"><span style="color: black;"> are (1, 2, 3, 4, 5, 6). <br />
The edges of the <i>Primitive</i> Magic Triangular Pyramid <b>Solution <span style="color: red;">B</span></b> are (1, 3, 5, 2, 4, 6).<br />
The edges of the <i>Primitive</i> Magic Triangular Pyramid <b>Solution <span style="color: red;">C</span></b> are (2, 4, 6, 1, 3, 5).<br />
The edges of the <i>Primitive</i> Magic Triangular Pyramid <b>Solution <span style="color: red;">D</span></b> are (4, 5, 6, 1, 2, 3).</span></span><br />
<br />
<span style="color: red;"><span style="color: black;"><span style="color: red;"><span style="color: black;"><a href="https://drive.google.com/file/d/1VGBK4QJcfLVNtixEWtntN4JszRoA3j-t/view?usp=sharing" rel="" target="_blank">The list of Magic Triangular Pyramids (MTP) found since the 27th August 2018</a>, uses the conventional edge length expressions described above. </span></span>It is intended to update this list from time to time to include the findings of others (should they agree to seeing their results published here). <span style="color: red;"><span style="color: black;">Any contributions will be much appreciated.</span></span></span></span></div>
</div>
<br />
<h3>
Further Developments</h3><br /><div style="text-align: justify;">
In February 2021 <a href="https://thecognitivecondition.com/" target="_blank">Steve Wait</a> informed me of his "Harmonious Pythagorean Triangular Pyramid Conjecture" and asked if I had any ideas concerning a degenerate pyramid threshold that he had observed. As I am not particularly skilled at trigonometry I took the liberty of forwarding Steve's question to <a href="http://www.trump.de/magic-squares/" target="_blank">Walter Trump</a>. Please refer to Steve Wait's site <a href="https://thecognitivecondition.com/" target="_blank">"The Cognitive Condition"</a> for more information on his very interesting <a href="https://thecognitivecondition.com/?p=64" target="_blank">"Precursory Study of Pythagorean Theorem Generalization as Consequence of Three-Dimensions"</a> and also for the details of Walter Trump's contribution to the understanding of <a href="https://thecognitivecondition.com/?p=230" target="_blank">the degenerate pyramid limits of the Pythagorean Pyramids</a>. <br /></div><div><p style="text-align: justify;">As for the Magic Triangular Pyramids, there is plenty of scope for further research: For those who are programmers there may be some interesting sequences to find in the evolution of the consecutive numbers of the 4 primitive Magic Triangular Pyramids. Other aspects, such as for example palindromic number solutions, remain to be investigated.</p></div>
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<div class="separator" style="clear: both; text-align: center;">
<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-2441424533824527452018-08-08T15:04:00.002+02:002023-06-19T23:04:19.164+02:00Magic Tetragonal Octahedra<div style="text-align: justify;">
On the 8th April 2018, I was one of several magic square enthusiasts to receive a copy of a paper entitled "Magic Tetragonal Octahedron" that was sent to us by <a href="https://www.region.com.ar/amela/franklinsquares/" rel="" target="_blank">Miguel Angel Amela</a>. Miguel is a prolific writer on recreational mathematics, and his papers are always a source of inspiration. This paper was no exception, as it prompted me to look into his subject, and make some humble contributions. What immediately interested me was that Magic Tetragonal Octahedra suggested possible links between numerical magic and geometry. Similar connections have already motivated my previous research in subjects that range from <a href="https://carresmagiques.blogspot.com/2020/04/from-magic-square-to-magic-torus.html" target="_blank">magic tori</a>, to <a href="https://carresmagiques.blogspot.com/2020/04/area-magic-squares-and-tori-of-order-3.html" target="_blank">area magic squares</a> and <a href="https://carresmagiques.blogspot.com/2020/04/perimeter-magic-squares.html" target="_blank">perimeter magic squares</a>. The third dimension of Magic Tetragonal Octahedra offers new possibilities.</div><br />
<div style="text-align: justify;"><h3>Magic Tetragonal Octahedra </h3><br />
In his paper dated 8th April 2018, Miguel points out that many parallels can be drawn between <a href="https://en.wikipedia.org/wiki/Magic_square" rel="" target="_blank">normal magic squares</a> and tetragonal octahedra. For example, in the <a href="https://en.wikipedia.org/wiki/Octahedron#Other_convex_octahedra" rel="" target="_blank">octahedral family</a>, the tetragonal types (known as tetragonal octahedra, or tetragonal trapezohedra, or tetragonal deltohedra) have 8 kite faces, 16 edges and 10 vertices. These totals can be compared with the 8 complementary pairs (for example 13 + 4 = n²+1), the 16 numbers (from 1 to 16), and the 10 magic line series (4 rows + 4 columns + 2 diagonals) that constitute a normal magic square of order-4. Miguel also observes that 8 faces + 16 edges + 10 vertices add up to 34, which is the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> of a normal magic square of order-4.</div><br />
<div style="text-align: justify;">If the 16 edges of a tetragonal octahedron are numbered from 1 to 16, and if each of the 8 faces has 4 edge numbers that total 34, then we are looking at a <i>Magic Tetragonal Octahedron. </i>Miguel's first example is illustrated below:<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhj9MKdlqptIw_arCO7Z62FV7Hv2NswG9WCcGaShufD6T-VXtguA4MWcm_Ni-BaDNMSuH2kOG7xDPtTSWlyOk39MBsnXLG8400FwGOquOUxofnWPEmGwWZL4bXKdCURR9j56GN9kDV2zVM/s1600/Panmagic-Tetragonal-Octahedron_og.png" style="margin-left: auto; margin-right: auto;"><img alt="Panmagic Tetragonal Octahedron" border="0" data-original-height="838" data-original-width="1600" height="268" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhj9MKdlqptIw_arCO7Z62FV7Hv2NswG9WCcGaShufD6T-VXtguA4MWcm_Ni-BaDNMSuH2kOG7xDPtTSWlyOk39MBsnXLG8400FwGOquOUxofnWPEmGwWZL4bXKdCURR9j56GN9kDV2zVM/s640/Panmagic-Tetragonal-Octahedron_og.png" title="" width="518" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Magic Tetragonal Octahedron by Miguel Angel Amela - Graphics by William Walkington</span></td></tr>
</tbody></table><br />
Miguel then checks if this Magic Tetragonal Octahedron is also <i>purely magic</i>. Purely magic is the term used by <a href="http://math.ut.ee/acta/16-1/Styan.pdf" rel="" target="_blank">George Styan</a> for magic squares where nM + N is magic, and M + nN is also magic, (when M and N are the basic matrices and n is the order of the square). For the first example of a Magic Tetragonal Octahedron (illustrated above), this is not the case, as shown by the factorization that follows:<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAf5GYSCj9bweInPH0ty6WH3a40UCU11hAG8c6IZV4ngEGtFlpXtyqC8FW2ZDd7soiYRLI6L0TQK8-PIQ6oZq3E2-dAX1xtnqnMKZcJ8VH7P2c8ewZ4r4erOTfWS38uwczG5HaLwB_l1M/s1600/Panmagic-Tetragonal-Octahedron-factorization.png" style="margin-left: auto; margin-right: auto;"><img alt="Panmagic Tetragonal Octahedron factorisation - not purely magic" border="0" data-original-height="1262" data-original-width="1600" height="403" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAf5GYSCj9bweInPH0ty6WH3a40UCU11hAG8c6IZV4ngEGtFlpXtyqC8FW2ZDd7soiYRLI6L0TQK8-PIQ6oZq3E2-dAX1xtnqnMKZcJ8VH7P2c8ewZ4r4erOTfWS38uwczG5HaLwB_l1M/s640/Panmagic-Tetragonal-Octahedron-factorization.png" title="" width="512" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Magic Tetragonal Octahedron Factorization by Miguel Angel Amela - Graphics by William Walkington</span></td></tr>
</tbody></table><i>Please note that for the factorization shown above, the natural numbers 1 to 16 are replaced by the numbers 0 to 15.</i> Miguel points out that in this example, the basic octahedral matrices are non-magic, and that when the multiplier is interchanged, the result B is not a Magic Tetragonal Octahedron. The octahedral matrices are not mutually orthogonal.<br />
<br />
Miguel then shows the factorization of a <i>Purely Magic</i> Tetragonal Octahedron, as illustrated below:<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgYP5Ebg5UuAgCSiiz3ZCPUBgBK83XlJhjLnIsviUM6a0W41KF2XGqyEbFOti8RzuOqJOIYxkBn7kIJKrOgUEpBSJ_PxbR8ZqEiul3BB-uOzKqKs-oUQZesDdbBE3cswgfx2RozpbxVGoI/s1600/Purely-Magic-Tetragonal-Octahedron-factorization.png" style="margin-left: auto; margin-right: auto;"><img alt="Purely Magic Tetragonal Octahedron factorisation" border="0" data-original-height="1261" data-original-width="1600" height="403" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgYP5Ebg5UuAgCSiiz3ZCPUBgBK83XlJhjLnIsviUM6a0W41KF2XGqyEbFOti8RzuOqJOIYxkBn7kIJKrOgUEpBSJ_PxbR8ZqEiul3BB-uOzKqKs-oUQZesDdbBE3cswgfx2RozpbxVGoI/s640/Purely-Magic-Tetragonal-Octahedron-factorization.png" title="" width="512" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Purely Magic Tetragonal Octahedron Factorization by Miguel Angel Amela - Graphics by William Walkington</span></td></tr>
</tbody></table><div class="separator" style="clear: both; text-align: center;"></div>In this second case, the basic octahedral matrices are magic, and when the multiplier is interchanged, the result D is also a <i>Purely Magic</i> Tetragonal Octahedron. The octahedral matrices are mutually orthogonal. <br />
<br />
In his conclusion, Miguel Angel Amela indicates that using a Quick Basic program with 9 independent variables, and compiled with QB64, he has found that the total number of Magic Tetragonal Octahedron solutions is <b>1,792</b> (8 x 224), and that <b>128</b> (8 x 16) of these are <i>Purely Magic</i>.<br />
<br />
Miguel states that his paper was inspired by a book that was sent to him by George Styan in 2012: This book by Fitting Friedrich is entitled <i>“Panmagische Quadrate und Magische Sternvielecke.”</i> The section that briefly describes Magic Tetragonal Octahedra is subtitled “Beziehung der magischen (8,2) - Sterne zu Körpern mit magischen Eigenschaften,” and can be found on the pages 62-63 of the 1939 edition of the Scientia Delectans, Germeinverständliche Darstellungen aus der Unterhaltungsmathematik und aux verwanden Gebieten, Heft 4.<br />
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<h3>Observations and Further Developments</h3><br />
Looking more closely at the examples given by Miguel Angel Amela I noticed something that had previously escaped my attention: I realised that 2 out of the 10 vertices of the Magic Tetragonal Octahedron were pole vertices where 4 edges met, whilst all of the other 8 vertices were the meeting points of only 3 edges. I therefore examined the pole vertices in more detail, using the same letters proposed by Miguel. For this study the polar vertices are therefore A and J:<br />
<br />
For the first Magic Tetragonal Octahedron (figure <b>A</b> in the first factorization):<br />
Pole vertex A: 2 + 10 + 3 + 15 = 30 (+ 4 for conversion) = 34 <i>the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> for magic squares of order-4</i><br />
Pole vertex J: 1 + 6 + 12 + 11 = 30 (+ 4 for conversion) = 34 <i>the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> for magic squares of order-4</i><br />
<br />
For the Purely Magic Tetragonal Octahedron (figure <b>C</b> in the second factorization):<br />
Pole vertex A: 2 + 11 + 8 + 15 = 36 (+ 4 for conversion) = 40<br />
Pole vertex J : 3 + 14 + 13 + 6 = 36 (+ 4 for conversion) = 40<br />
<br />
For the Purely Magic Tetragonal Octahedron (figure <b>D</b> in the second factorisation):<br />
Pole vertex A: 8 + 14 + 2 + 15 = 39 (+ 4 for conversion) = 43<br />
Pole vertex J : 12 + 11 + 7 + 9 = 39 (+ 4 for conversion) = 43<br />
<br />
On the 9th June 2018 I contacted Miguel to inform him about these observations, and to ask him, if he had the time, to use his programming skills to discover the answers to the following questions:<br />
1/ Did the total of the edges that meet at pole A always equal the total of edges that meet at pole J?<br />
2/ If so, what were the subtotals of the 1792 Magic Tetragonal Octahedra for each of the polar sums?<br />
<br />
In the days that followed Miguel investigated further, and then wrote back to inform me that:<br />
1/ For all 1792 solutions, the sum of the 4 edges of pole A = the sum of the 4 edges of pole J. <br />
2/ For Magic Tetragonal Octahedra constructed using consecutive natural numbers from 1 to 16, the number of solutions is symmetric, with polar sums ranging from 19 to 49 (<i>except for 20 or 48, which strangely do not exist</i>), and the 288 solutions which have the polar sum of 34 (the <a href="https://en.wikipedia.org/wiki/Magic_constant" rel="" target="_blank">magic constant</a> of magic squares of order-4) <i>are at the centre of this system</i>. What is more, each of the solutions with polar sums of 34 has interesting equatorial symmetries:<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWDujQBnuuedvhlhbWiTPPs7pMZh3fcixQczKloTttcuBfiEEfa33dw7dH-X5ppAG0gtVl36qXHypHPk6fTo-vt2j5J5XSuTVGx4IeZ2Mw4oJoCidmD7E40eYZcq76UcXIB_2NdjMz-no/s1600/Magic-Tetragonal-Octahedra-polar-sums.png" style="margin-left: auto; margin-right: auto;"><img alt="This is a table of the polar sums of the 1792 Magic Tetragonal Octahedra. 288 solutions are Panmagic, and these have special magic symmetries." border="0" data-original-height="1600" data-original-width="1172" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWDujQBnuuedvhlhbWiTPPs7pMZh3fcixQczKloTttcuBfiEEfa33dw7dH-X5ppAG0gtVl36qXHypHPk6fTo-vt2j5J5XSuTVGx4IeZ2Mw4oJoCidmD7E40eYZcq76UcXIB_2NdjMz-no/s400/Magic-Tetragonal-Octahedra-polar-sums.png" title="" width="291" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Table of the polar sums of Magic Tetragonal Octahedra by Miguel Angel Amela - Graphics by William Walkington</span></td></tr>
</tbody></table><br />
The 288 "most-magic" solutions with magic polar sums of 34 are particularly interesting, and Miguel and I have therefore decided to call these <i>Panmagic Tetragonal Octahedra</i>: Please refer to the very first figure of this post which, by a complete coincidence, turns out to be a good example!<br />
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<h3>What are the Possible Implications of an Irregular Magic Tetragonal Octahedron? </h3><br />
On the 8th April 2018 I had another question for Miguel: <i>"Is it possible to draw irregular Magic Tetragonal Octahedra using lines that have lengths in proportion to the numbers 1 to 16? And if this is possible, and the faces are still planar, what are the implications for the areas of the faces?"</i><br />
<i><br />
</i> For the time being, at the date of posting this article, this question remains unanswered. I have attempted to construct a virtual model using Sketchup and Autocad, but the exercise is too difficult without precise coordinates for the vertices. I have also tried to physically construct a scale model, but was faced with a practical problem: As the octahedron kite edges lack <a href="https://sites.google.com/site/stuctures2esomartinaanddaniela/5-the-design-of-frame-structures-triangulation" rel="" target="_blank">structural triangulation</a>, the resulting instability is an impediment to making accurate measurements... Apparently the solution will have to come from an algorithm that will produce precise coordinates of the vertices, depending on the relative positions of the edges 1 to 16. And once this is achieved, we should be able to construct the irregular polyhedron and answer the following questions:<br />
<br />
Are the 8 kite faces continuous or folded planar surfaces?<br />
Do the kite areas have special characteristics?<br />
Does the volume of the irregular Magic Tetragonal Octahedron have special characteristics?<br />
<i><br />
</i> <i>Should a reader wish to contribute, please send me the precise x, y and z coordinates of the vertices that define an irregular Panmagic Tetragonal Octahedron. No prizes can be given, but the authors of pertinent solutions will, if they agree, have their findings published here.</i><br />
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<h3>Acknowledgement<i> </i></h3><br />
I wish to thank Miguel Angel Amela for bringing this interesting aspect of magic geometry to my attention, and for authorising me to publish the contents of his paper.</div>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-79530585454673857252018-01-21T14:36:00.002+01:002023-06-19T23:05:28.688+02:00Multiplicative Magic Tori<div style="text-align: justify;"><span style="font-weight: normal;">Because the present-day definition of complementary and self-complementary magic squares can be over-restrictive when studying magic tori, an alternative modular arithmetic interpretation is therefore proposed.</span></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><span style="font-weight: normal;">This approach suggests a new direction for research on magic squares (or magic tori), using modular multiplication, modular addition, and modular exponentiation.</span></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><span style="font-weight: normal;">Multiplicative Magic Tori (MMT) are examined throughout the orders 1 to 4. (Although there is no magic torus of order-2, there is a Multiplicative Diagonally Semi-Magic Torus (MDSMT)). The study then continues with a partial inspection of various examples from higher-orders, including some bimagic MMT of order-8.</span><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimqwC5CYhFX7IQTcmI8kdv8WwxaZeG1Jfp4nRU6vTdwdhyphenhyphenQ5O-uDi5Z-eb2PJnh9B-uxMkmYKfv7JHg3743d8M9NkE6KSvTffWbYnnYIs-svTshrjzz3l07TxpMcjToECq9HB8scOceGg/s1600/Example+of+multiplicative+magic+torus+or+magic+square_og.png" style="margin-left: auto; margin-right: auto;"><img alt="Modular multiplication and modular addition of magic tori or magic squares in order 4" border="0" data-original-height="835" data-original-width="1600" height="259" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimqwC5CYhFX7IQTcmI8kdv8WwxaZeG1Jfp4nRU6vTdwdhyphenhyphenQ5O-uDi5Z-eb2PJnh9B-uxMkmYKfv7JHg3743d8M9NkE6KSvTffWbYnnYIs-svTshrjzz3l07TxpMcjToECq9HB8scOceGg/s640/Example+of+multiplicative+magic+torus+or+magic+square_og.png" title="" width="500" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: #0000ee;"><span style="font-size: xx-small;">A typical Multiplicative Magic Torus (MMT), or Multiplicative Magic Square (MMS) of order-4</span></span></td></tr>
</tbody></table></div><div style="text-align: justify;"><span style="font-weight: normal;">The results include a new census of the Multiplicative Magic Tori (MMT) and Multiplicative Magic Squares (MMS) of orders 1 to 4. A detailed classification of the 82 Multiplicative Magic Tori (MMT) and 220 Multiplicative Magic Squares (MMS) of order-4 is given, together with explanatory graphics that highlight the main relationships and links.</span></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><span style="font-weight: normal;">In addition, it is shown that the digonally magic, diagonally semi-magic, and lesser-magic tori, which are also present on the MMT, have special orthogonal sums. Some other interesting characteristics of modular exponentiations are also examined and commented.</span></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><span style="font-weight: normal;">The conclusions are presented in the form of integer sequences. Any input that might confirm, correct, or usefully append these findings, would be much appreciated.</span><br />
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<h3><span style="font-weight: normal;"><u><b>Multiplicative Magic Tori</b></u> </span></h3></div><br />
<div style="text-align: justify;"><span style="font-weight: normal;">Please note that if you click on the button that appears at the top right hand side of the pdf viewer below, a new window will open and full size pages of <a href="https://drive.google.com/file/d/1CLhck41V8LwIzfrqRRvAArqDsEeVEZ0F/view?usp=sharing" rel="" target="_blank">"Multiplicative Magic Tori"</a> will then be displayed, with options for zooming.</span></div><br />
<iframe height="405px" src="https://docs.google.com/viewer?srcid=1CLhck41V8LwIzfrqRRvAArqDsEeVEZ0F&pid=explorer&efh=false&a=v&chrome=false&embedded=true" width="518px"></iframe>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-69904208798615417552017-09-11T14:13:00.003+02:002023-06-19T23:06:25.366+02:00Paired and Self-Complementary Magic Tori of Order-4<div style="text-align: justify;">In his paper <a href="http://web.archive.org/web/20011115232337/http://www.pse.che.tohoku.ac.jp/~msuzuki/MagicSquare.4x4.selfcompl.html" rel="" target="_blank">"Self-complementary magic squares of 4x4,"</a> Mutsumi Suzuki has shown that there are 352 self-complementary magic squares of order-4. Although Suzuki does not use <a href="https://en.wikipedia.org/wiki/Fr%C3%A9nicle_standard_form" rel="" target="_blank">Frénicle standard form</a>, his examples are essentially different, and the total of these 352 self-complementary squares can therefore be compared with the grand total of the <a href="https://books.google.fr/books?id=XSwIkqHb_XsC&pg=PA303&dq=table+generale+des+quarrez+de+quatre&hl=fr&sa=X&ved=0ahUKEwih4KrZlZ3WAhXLIMAKHbGnBRQQ6AEILTAB#v=onepage&q=table%20generale%20des%20quarrez%20de%20quatre&f=false" rel="" target="_blank">880 essentially different magic squares of order-4</a> previously identified by Bernard Frénicle de Bessy.</div><br />
<div style="text-align: justify;">On his page <a href="http://www.magic-squares.net/Self-similar.htm" rel="" target="_blank">"Self-Similar Magic Squares,"</a> Harvey Heinz has studied Mutsumi Suzuki’s work, and points out that the 352 self-complementary magic squares include 48 Dudeney Type III associated semi-pandiagonal, 96 Dudeney Type VI semi-pandiagonal, and 208 Dudeney Type VI “simple” magic squares. The Dudeney Types referred to by Harvey Heinz come from Henry Dudeney’s classification of the 880 Frénicle magic squares into <a href="https://archive.org/stream/AmusementsInMathematicspdf/AmusementsInMathematics#page/n175/mode/2up/search/Magic+square+problems" rel="" target="_blank">12 types</a><span lang="EN-GB" style="font-family: "times new roman"; font-size: small; mso-ansi-language: EN-GB; mso-bidi-language: AR-SA; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: FR;"></span>, each of which corresponds to a different complementary number pattern.</div><br />
<div style="text-align: justify;">Today we know that the 880 Frénicle indexed magic squares are partial viewpoints of <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">255 essentially different magic tori of Order-4</a> (OEIS sequence <a href="http://oeis.org/A270876" rel="" target="_blank">A270876</a>). A previous post <a href="https://carresmagiques.blogspot.com/2020/04/complementary-number-patterns-on-4th-order-magic-tori.html" target="_blank">"Complementary Number Patterns on Fourth-Order Magic Tori"</a> has shown that some of the 12 Dudeney complementary number patterns become redundant on fourth-order magic tori, and this has resulted in the creation of a new reduced set of complementary number pattern types which are better adapted:<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiN15f-LUTAVcCP3frWVtoMOSXvaXLbWTKte7QAFHuKkyCzswF9aGxE0zsDFulCF46g4Mx8eOskQiJE_7kVGJncyA35vYDMwhuHDYJfLxYxbTMcDi9Y_2kiTslFwcpoUobNRxZVJyYlVQM/s1600/new_complementary_number_patterns_magic_tori_order-4_1.png" style="margin-left: 1em; margin-right: 1em;"><img alt="New order-4 magic torus complementary number patterns types I to II replace former Dudeney patterns for magic squares." border="0" data-original-height="836" data-original-width="1600" height="195" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiN15f-LUTAVcCP3frWVtoMOSXvaXLbWTKte7QAFHuKkyCzswF9aGxE0zsDFulCF46g4Mx8eOskQiJE_7kVGJncyA35vYDMwhuHDYJfLxYxbTMcDi9Y_2kiTslFwcpoUobNRxZVJyYlVQM/s320/new_complementary_number_patterns_magic_tori_order-4_1.png" title="" width="375" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh4TX_TSxuomscWDrGdqVVAy4lLbCUeNBwc6HTqa5ABYh50SMOP3Cx1owWMA_jsDds34Qzh5Wq0hYZnThyRKDWDf7dbTKQsxrhjwHdjKSEQBjGVkI7ru7vYU5WruSuzawfIGPeFr0lpWx4/s1600/new_complementary_number_patterns_magic_tori_order-4_2.png" style="margin-left: 1em; margin-right: 1em;"><img alt="New order-4 magic torus complementary number patterns types III to VIII replace former Dudeney patterns for magic squares." border="0" data-original-height="1600" data-original-width="1549" height="416" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh4TX_TSxuomscWDrGdqVVAy4lLbCUeNBwc6HTqa5ABYh50SMOP3Cx1owWMA_jsDds34Qzh5Wq0hYZnThyRKDWDf7dbTKQsxrhjwHdjKSEQBjGVkI7ru7vYU5WruSuzawfIGPeFr0lpWx4/s320/new_complementary_number_patterns_magic_tori_order-4_2.png" title="" width="402" /></a></div><br />
Therefore, with less complementary number patterns, what are the implications for the totals of self-complementary and paired complementary magic tori of order-4? In the study that follows, all of the 255 magic tori of order-4 are listed, and the details of their complements are given. In the final observations, the different cases of self-complementarity or paired complementarity are analysed, together with the respective complementary number patterns.</div><div style="text-align: justify;"><br />
<div class="separator" style="clear: both; text-align: center;"></div></div><div style="text-align: justify;">Please note that if you click on the button that appears at the top right hand side of the pdf viewer below, a new window will open and full size pages of the paper <a href="https://drive.google.com/file/d/1Rlfz73ggHUn1-SJkWqLwTCE_HP_3lqyS/view?usp=sharing" rel="" target="_blank">"Self-Complementary and Paired Complementary Magic Tori of Order-4"</a> will then be displayed, with options for zooming.</div><br />
<iframe height="653px" src="https://docs.google.com/viewer?srcid=1Rlfz73ggHUn1-SJkWqLwTCE_HP_3lqyS&pid=explorer&efh=false&a=v&chrome=false&embedded=true" width="518px"></iframe>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-66801269546656114752017-03-09T13:55:00.004+01:002023-06-19T23:07:11.924+02:00Perimeter Magic Squares<div style="text-align: justify;">After the first discoveries of <a href="https://carresmagiques.blogspot.com/2020/04/area-magic-squares-and-tori-of-order-3.html" target="_blank">area magic squares</a>, I decided to do some more exploring and search for examples of perimeter magic squares. I found that the latter do indeed exist, and that although these appear to be similar to linear area magic squares, their construction is quite different for two reasons: Depending on the slopes (and lengths) of the slanting dissection lines of a perimeter magic square, the hinge points of these lines are offset when compared with those of an area magic square. The total perimeter of a perimeter magic square results from the slopes (and lengths) of the slanting dissection lines, and not from the addition of the individual cell perimeters.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Unless stated otherwise, the perimeter magic squares illustrated here have been created by the author of this post. Although perimeter magic squares are shown to be different from area magic squares, they were deduced using <a href="http://www.trump.de/magic-squares/area-magic/index.html" rel="" target="_blank">Walter Trump's</a> area magic square construction techniques.</div><div style="text-align: justify;"><br />
For want of a better word, please note that these perimeter magic squares are <i>measured geometric perimeter</i> magic squares, and that they are therefore not to be confused with the square examples of perimeter-magic polygons, (first created by <a href="https://web.archive.org/web/20160323223944/http://www.trottermath.net/simpleops/pmp.html" rel="" target="_blank">Terrel Trotter Jr.</a> and further discussed on the website of <a href="http://www.magic-squares.net/perimeter-2.htm" rel="" target="_blank">Harvey Heinz</a>).</div><br />
<h3 style="text-align: justify;"><u>Linear Perimeter Magic Square of Order-3</u></h3><br />
<div style="text-align: justify;">On the 25th February 2017, the first Linear Perimeter Magic Square (L-PMS) of Order-3 was constructed using AutoCAD:</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj0fR-icBbZycMfQ1xuaFSERYS9uvVY7zN1Hz2PNLAsM_2Hmf1mgU0mWHz2D3Lm1kHxxmLbk-IBWnns1zDJ_ZgYRQpVeN1J7oDbIhtfCXyt9h1nHLYSZZHU4bLwK-fwfJ_e2zVLfHnyv2c/s1600/WW_order_3_perimeter_magic_square_S48_170225.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="Linear Perimeter Magic Square of Order-3 with magic sum S=48" border="0" data-original-height="841" data-original-width="1600" height="272" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj0fR-icBbZycMfQ1xuaFSERYS9uvVY7zN1Hz2PNLAsM_2Hmf1mgU0mWHz2D3Lm1kHxxmLbk-IBWnns1zDJ_ZgYRQpVeN1J7oDbIhtfCXyt9h1nHLYSZZHU4bLwK-fwfJ_e2zVLfHnyv2c/s640/WW_order_3_perimeter_magic_square_S48_170225.jpg" title="" width="518" /></a></div><div style="text-align: justify;">This L-PMS is drawn to a precision of 2 decimal places for each of the 9 cell perimeters, and the resulting total perimeter of the square is therefore approximately 47.372 (before computer validation and optimisation). The coordinates of this square are available upon request.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Maybe the square perimeters of such L-PMS of order-3 are proportional to the regular consecutive number cell perimeter sequences that they display, and those amongst you with programming skills will be able to generate different similarly-constructed examples, and thus identify the relationship?</div><br />
<h3 style="text-align: justify;"><u>Linear Perimeter Magic Squares of Order-4</u></h3><br />
<div style="text-align: justify;"><span style="font-weight: normal;">The following Semi-Orthogonal Linear Perimeter Magic Squares (L-PMS) of order-4 <i>have cell perimeter entries rounded to 6 digits</i>. Because their central slanted lines are not derived from Pythagorean triangles, the lengths of the adjoining cell perimeters are not finite integers, but irrational "infinite" numbers. The precision of the cell perimeters can be further increased, but with each increase in precision the cell entries and the corresponding magic sums become higher, and the dimensions have to be modified accordingly.</span></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><span style="font-weight: normal;">Constructed on the 23rd February 2017, the following L-PMS of order-4 has a rounded magic sum of S = 1936532:</span></div><br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikZsLFdMrrMqMg2ExkwQZBhqW7SxKJ_3JwnvXvK95Zjqe3Z9zK7DYrkeLytPcj7-C-7WWagGu9PZ-6huTl9mcGLvdb2kRP-9kuY8hXY0GjueOTspIRlLXlISzEPTQbsC9fqAdJ0ewmXt0/s1600/WW_order_4_perimeter_magic_square_S1936532_170223.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Semi-Orthogonal Linear Perimeter Magic Square of Order-4 constructed using Pythagorean triangles" border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikZsLFdMrrMqMg2ExkwQZBhqW7SxKJ_3JwnvXvK95Zjqe3Z9zK7DYrkeLytPcj7-C-7WWagGu9PZ-6huTl9mcGLvdb2kRP-9kuY8hXY0GjueOTspIRlLXlISzEPTQbsC9fqAdJ0ewmXt0/s320/WW_order_4_perimeter_magic_square_S1936532_170223.png" title="Linear Perimeter Magic Square of Order-4 with magic sum S=1936532" width="290" /></a></div><div style="text-align: justify;"><span style="font-weight: normal;"><br />
</span><span style="font-weight: normal;"> </span> <span style="font-weight: normal;">The upper slanted line is derived from a Pythagorean triangle with long leg 24, short leg 7, and hypotenuse 25. The central slanted line is derived from a triangle with long leg 120, short leg 8, and hypotenuse 120.26637102698... The lower slanted line is derived from a Pythagorean triangle with long leg 40, short leg 9, and hypotenuse 41. The total sum of the 16 cell perimeters is 1936532 x 4 = 7746128. The average cell perimeter is 7746128 / 16 = 484133. The perimeter of the magic square is 120000 x 4 x 4 = 1920000. The coordinates of this square are available upon request. This perimeter magic square's cell values are voluntarily rounded to 6 digits. Greater accuracy is possible, but this will inevitably lead to very high entries. If more or less digits are used for the cell perimeter values, then the slanted lines will need vertical translations to take into account the revised magic sums, and this will imply new dimensions. There are some interesting relationships between the broken diagonals of this linear perimeter magic square (L-PMS), as shown in the following diagram: </span></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimeNnvWdnTdRq4tK9IUUkUisHPZakqYMot0xlWndhnA6vyNRLvl2qwx13rmH65UWNp-jnmP8WJWgEuoBN1Zkq4WjngQNVbqVB2DOoDtmP30UMfsMuln-TGH9QQRCPBStEAy-YsBIcMH1c/s1600/diagonals_perimeter_magic_square_order_4_S1936532.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="Diagonals of linear perimeter magic square of order-4 with magic sum S=1936532" border="0" height="312" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimeNnvWdnTdRq4tK9IUUkUisHPZakqYMot0xlWndhnA6vyNRLvl2qwx13rmH65UWNp-jnmP8WJWgEuoBN1Zkq4WjngQNVbqVB2DOoDtmP30UMfsMuln-TGH9QQRCPBStEAy-YsBIcMH1c/s320/diagonals_perimeter_magic_square_order_4_S1936532.jpg" title="" width="320" /></a></div><br />
<div style="text-align: justify;">Constructed on the 24th February 2017, the following L-PMS of order-4 has a rounded magic sum of S = 1930156:</div><br />
<div class="separator" style="clear: both; text-align: center;"><span style="font-weight: normal;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjuYdXLCg_o4KtST-VDozkAtz6jFVVL9MWpW-Fr8TVc-PdmaBhKO4S4-N2M-F-ucEkSlvzRRqXCtQt0y0nNVDHGWMYSjzdZ5oj_ro80L_354PepJXUBqNXiw4ZfjFoU43uOFqe5DRJpYhU/s1600/WW_order_4_perimeter_magic_square_S1930156_170224+.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Semi-Orthogonal Linear Perimeter Magic Square of Order-4 constructed using Pythagorean triangles" border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjuYdXLCg_o4KtST-VDozkAtz6jFVVL9MWpW-Fr8TVc-PdmaBhKO4S4-N2M-F-ucEkSlvzRRqXCtQt0y0nNVDHGWMYSjzdZ5oj_ro80L_354PepJXUBqNXiw4ZfjFoU43uOFqe5DRJpYhU/s320/WW_order_4_perimeter_magic_square_S1930156_170224+.png" title="Linear Perimeter Magic Square of Order-4 with magic sum S=1930156" width="291" /></a></span></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The upper slanted line is derived from a Pythagorean triangle with long leg 1200, short leg 49, and hypotenuse 1201. The central slanted line is derived from a triangle with long leg 120, short leg 26.9, and hypotenuse 122.978087479... The lower slanted line is derived from a Pythagorean triangle with long leg 60, short leg 11, and hypotenuse 61. The total sum of the 16 cell perimeters is 1930156 x 4 = 7720624. The average cell perimeter is 7720624 / 16 = 482539. The perimeter of the magic square is 120000 x 4 x 4 = 1920000.<span style="font-weight: normal;"> The coordinates of this square are available upon request. This perimeter magic square's cell values are voluntarily rounded to 6 digits. Greater accuracy is possible, but this will inevitably lead to very high entries. If more or less digits are used for the cell perimeter values, then the slanted lines will need vertical translations to take into account the revised magic sums, and this will imply new dimensions. There are some interesting relationships between the broken diagonals of this linear perimeter magic square (L-PMS), as shown in the following diagram: </span></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgifmti6U10LrKVWl-7RVNSrQeQsiuPrHalA-FsExhE_tGXcXUzlyzj-7Au24stG8L4y6bm2lct-CRwaLqAEQyDi4voQo3Bz6HBZmz8zqiGMkHakFimZG1K-1rO28tuzn2bwSfftQPRnKY/s1600/diagonals_perimeter_magic_square_order_4_S1930156.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="Diagonals of linear perimeter magic square of order-4 with magic sum S=1930156" border="0" height="312" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgifmti6U10LrKVWl-7RVNSrQeQsiuPrHalA-FsExhE_tGXcXUzlyzj-7Au24stG8L4y6bm2lct-CRwaLqAEQyDi4voQo3Bz6HBZmz8zqiGMkHakFimZG1K-1rO28tuzn2bwSfftQPRnKY/s320/diagonals_perimeter_magic_square_order_4_S1930156.jpg" title="" width="320" /></a></div><br />
<div style="text-align: justify;"><span style="font-weight: normal;">Perhaps a reader with programming skills will be tempted to find the first semi-orthogonal linear perimeter magic square of order-4 with all slanted diagonals derived from Pythagorean triangles, and therefore endowed with finite integer values for its cell entries?</span></div><br />
<h3 style="text-align: justify;"><u>Linear Perimeter Semi-Magic Squares of Order-4</u></h3><br />
<div style="text-align: justify;"><span style="font-weight: normal;">For comparison with the above examples of linear perimeter magic squares with rounded cell entries, the following linear perimeter <i>semi-magic</i> squares of order-4 are each constructed with all three slanting lines derived from Pythagorean triangles. Their individual cell perimeters can thus be defined as integers, and the resulting cell entries and magic sums of these perimeter <i>semi-magic</i> squares are therefore rational and finite.</span></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><span style="font-weight: normal;">Constructed on the 24th February 2017, the following linear perimeter semi-magic square (L-PSMS) has a magic sum of S = 15492:</span></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjxACUPdgl9vmS-yTy3GPkNWHVUxpMLxxUzEQYp1UNCctOXQUbYyl5DAdXZg7X2SHnJtva7ed3NMe13Rb7ATLJcomQ8gu8UmLDf5oG_oUR0iVaVYkJvKjKBHoTP7A7W7Tu-CCm2ygDK3Po/s1600/WW_order_4_perimeter_semi-magic_square_S15492_170224.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Semi-Orthogonal Linear Perimeter Semi-Magic Square of Order-4 constructed using Pythagorean triangles" border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjxACUPdgl9vmS-yTy3GPkNWHVUxpMLxxUzEQYp1UNCctOXQUbYyl5DAdXZg7X2SHnJtva7ed3NMe13Rb7ATLJcomQ8gu8UmLDf5oG_oUR0iVaVYkJvKjKBHoTP7A7W7Tu-CCm2ygDK3Po/s320/WW_order_4_perimeter_semi-magic_square_S15492_170224.png" title="Linear Perimeter Semi-Magic Square of Order-4 with magic sum S=15492" width="290" /></a></div><br />
<div style="text-align: justify;"><span style="font-weight: normal;">The upper slanted line is derived from a Pythagorean triangle with long leg 24, short leg 7, and hypotenuse 25. The central slanted line is derived from a Pythagorean triangle with long leg 480, short leg 31, and hypotenuse 481. The lower slanted line is derived from a Pythagorean triangle with long leg 40, short leg 9, and hypotenuse 41. The total sum of the 16 cell perimeters is 15492 x 4 = 61968. The average cell perimeter is 61968 / 16 = 3873. The perimeter of the semi-magic square is 960 x 4 x 4 = 15360. The coordinates of this square are available upon request. There are some interesting relationships between the broken diagonals of this linear perimeter semi-magic square (L-PSMS), as shown in the following diagram: </span></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvjLQ9IRTzQM3Cvop2ngsNG2OxPJPQDt6HrRNgAHHUXEpbv0tHZd173pLT4LOTxWJTwC0r-M2L9UxxnKZaGJDQhnk7RQX2mMFTnds0QbmBDGxCyDkqAmUjF3JVc-e45r1x21OrR4tvGk4/s1600/diagonals_perimeter_semi-magic_square_order_4_S15492.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="Diagonals of linear perimeter semi-magic square of order-4 with magic sum S=15492" border="0" height="261" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvjLQ9IRTzQM3Cvop2ngsNG2OxPJPQDt6HrRNgAHHUXEpbv0tHZd173pLT4LOTxWJTwC0r-M2L9UxxnKZaGJDQhnk7RQX2mMFTnds0QbmBDGxCyDkqAmUjF3JVc-e45r1x21OrR4tvGk4/s320/diagonals_perimeter_semi-magic_square_order_4_S15492.jpg" title="" width="320" /></a></div><br />
<div style="text-align: justify;"><span style="font-weight: normal;">Also constructed on the 24th February 2017, the following linear perimeter semi-magic square (L-PSMS) has a magic sum of S = 970:</span></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvZXDsMb053XQePzgzMMmP0wQvsyLRrro38y4RVS0-jexXK1GM7-ZwyYxl0FZ9YCBZrKduNkxFiFfdZMR7BV5kafF9rWfCoUPJNeW2BfCursAg7wUfajhJLphdVMjfvzFh-kACvZSylWQ/s1600/WW_order_4_perimeter_semi-magic_square_S970_170224.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Linear perimeter semi-magic square using Pythagorean triangles" border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvZXDsMb053XQePzgzMMmP0wQvsyLRrro38y4RVS0-jexXK1GM7-ZwyYxl0FZ9YCBZrKduNkxFiFfdZMR7BV5kafF9rWfCoUPJNeW2BfCursAg7wUfajhJLphdVMjfvzFh-kACvZSylWQ/s320/WW_order_4_perimeter_semi-magic_square_S970_170224.png" title="Linear perimeter semi-magic square (L-PSMS) of order 4" width="288" /></a></div><br />
<div style="text-align: justify;"><span style="font-weight: normal;">The upper slanted line is derived from a Pythagorean triangle with long leg 40, short leg 9, and hypotenuse 41. The central slanted line is derived from a Pythagorean triangle with long leg 60, short leg 11, and hypotenuse 61. The lower slanted line is derived from a Pythagorean triangle with long leg 24, short leg 7, and hypotenuse 25. The total sum of the 16 cell perimeters is 970 x 4 = 3880. The average cell perimeter is 3880 / 16 = 242.5. The perimeter of the semi-magic square is 60 x 4 x 4 = 960. The coordinates of this square are available upon request. There are some interesting relationships between the broken diagonals of this linear perimeter semi-magic square (L-PSMS), as shown in the following diagram: </span></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEho4ZhIm7U6hqk477o20FYmY4VWrz5Ha211qPfUvx3dPSvLC4stBVH3wwWqq0I6rfmC0kPWoLpZj-5wQTQnrXY5xjxpE7vMz-CIYSEZV-6KrZUyvkxUWLPElLxwkoGBgEbEof_3izrgkio/s1600/diagonals_perimeter_semi-magic_square_order_4_S970.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="Diagonals of linear perimeter semi-magic square of order-4 with magic sum S=970" border="0" height="285" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEho4ZhIm7U6hqk477o20FYmY4VWrz5Ha211qPfUvx3dPSvLC4stBVH3wwWqq0I6rfmC0kPWoLpZj-5wQTQnrXY5xjxpE7vMz-CIYSEZV-6KrZUyvkxUWLPElLxwkoGBgEbEof_3izrgkio/s320/diagonals_perimeter_semi-magic_square_order_4_S970.jpg" title="" width="320" /></a></div><span style="font-weight: normal;"><i></i></span> <br />
<h3 style="text-align: justify;"><u>Further Developments</u> </h3><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><span style="font-weight: normal;">If anyone wishes to contribute linear or strict geometrical constructions of other perimeter magic squares, then please send me the x and y coordinates of the cell intersections that define the perimeters correctly up to two or more decimal places. No prizes can be given, but the authors of pertinent solutions will, if they wish, have their solutions published here.</span></div><div style="text-align: justify;"><span style="font-weight: normal;"><i><br />
</i></span></div><div style="text-align: justify;">A new post on <a href="https://carresmagiques.blogspot.com/2022/06/polyomino-area-magic-tori.html" target="_blank">"Polyomino Area Magic Tori"</a> (PAMT) can be found in this blog since the 7th June 2022. Perhaps these PAMT will suggest new possibilities for the exploration of polyomino perimeter magic squares (PPMS) and polyomino perimeter magic tori (PPMT)...<span style="font-weight: normal;"><i>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-54815611449938549762017-02-08T13:38:00.004+01:002023-06-19T23:07:53.808+02:00Area Magic Squares of Order-4<div style="text-align: justify;">
Further to the discoveries of the <a href="https://carresmagiques.blogspot.com/2020/04/area-magic-squares-and-tori-of-order-3.html" target="_blank">area magic squares of order-3</a>, the first linear area magic square of order-4 was found by Walter Trump on the 14th January 2017.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOvTh1h7lAeZBIw3V518OZibWQYMSti8pTdLYl2XtdJL3O0MmDk5jQKH6iWEsoIb3VZnyZxeItpA94ALvFDhwEVnLuEd1XuOsIxje8bxkufz9QaKOBf_ugBziUlR9SyAg-Cp6Uqxoi4Kw/s1600/WT_order_4_linear_area_magic_square_S96_170114.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Linear area magic square (L-AMS) of order 4" border="0" data-original-height="836" data-original-width="1600" height="208" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOvTh1h7lAeZBIw3V518OZibWQYMSti8pTdLYl2XtdJL3O0MmDk5jQKH6iWEsoIb3VZnyZxeItpA94ALvFDhwEVnLuEd1XuOsIxje8bxkufz9QaKOBf_ugBziUlR9SyAg-Cp6Uqxoi4Kw/s400/WT_order_4_linear_area_magic_square_S96_170114.png" title="" width="400" /></a></div></div><br />
<div style="text-align: justify;">On the 15th January 2017, Walter Trump's computer program was able to produce thousands of 4x4 linear area magic squares. Meanwhile, he was joined by fellow mathematician and programmer Hans-Bernhard Meyer, who on the 16th January 2017, found a different type of 4x4 linear area magic square (L-AMS). From then on Walter and Hans-Bernhard worked in collaboration, and they have kindly authorised me to illustrate samples of their findings below:</div><br />
<div style="text-align: justify;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimoBf1-e37Y2rPOEhPOwo3wpxygZfwP1JMDCekdsh7gThCufmuDViiuxXFzYuXjo5Kq3Oa7B0MnovmQTXui4Dr7Iu1uDKK3UCT4F_j21pB0sxE1pWjt4nzeZx8lxMZZz9o6rTOaqlZzGI/s1600/WT_order_4_linear_area_magic_square_S84_170116.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Linear area magic square of order 4 with magic constant S=84" border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimoBf1-e37Y2rPOEhPOwo3wpxygZfwP1JMDCekdsh7gThCufmuDViiuxXFzYuXjo5Kq3Oa7B0MnovmQTXui4Dr7Iu1uDKK3UCT4F_j21pB0sxE1pWjt4nzeZx8lxMZZz9o6rTOaqlZzGI/s200/WT_order_4_linear_area_magic_square_S84_170116.png" title="Linear area magic square (L-AMS) of order 4" width="182" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgK_rJYKGAh7sXpp6RILcj7v8ks9MjW89DY160WmRByQJv68H9PSHLD1t904iyvsXoCtWTwa-ANCUCnWkCIHDVfyzEw1QETFUrTWEZBdhEKZBmozHcj8guIkC4ZPPjf_GqwZCIvrL8ZJiI/s1600/WT_order_4_linear_area_magic_square_S100_170116.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Fourth-order linear area magic square (L-AMS) with magic constant S=100" border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgK_rJYKGAh7sXpp6RILcj7v8ks9MjW89DY160WmRByQJv68H9PSHLD1t904iyvsXoCtWTwa-ANCUCnWkCIHDVfyzEw1QETFUrTWEZBdhEKZBmozHcj8guIkC4ZPPjf_GqwZCIvrL8ZJiI/s200/WT_order_4_linear_area_magic_square_S100_170116.png" title="Linear area magic square of order 4" width="181" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwn9ekdqin9oTaw2-WokzNiX3HakM58zDAN2yGNUfYgew_1FSKpeUtBR5O7cKPrVIlD63ydtTaexEBz6M0AZjzBuxmkfhAkMh90LkhkAlKoS_FY8Vte9njMnzITRMP0FKhI45BEbusZxs/s1600/H-BM_order_4_linear_area_magic_square_S100_170116.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Order 4 linear area magic square (L-AMS) with magic constant S = 100" border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwn9ekdqin9oTaw2-WokzNiX3HakM58zDAN2yGNUfYgew_1FSKpeUtBR5O7cKPrVIlD63ydtTaexEBz6M0AZjzBuxmkfhAkMh90LkhkAlKoS_FY8Vte9njMnzITRMP0FKhI45BEbusZxs/s200/H-BM_order_4_linear_area_magic_square_S100_170116.png" title="" width="185" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOUFfe5ytOY8D0Tkhl20zupZPm5xmozPUhk14_buM9mStEGJjSKqleyTNm-mLqX3ugGWvOP-1kDU-7QpZMbX3ZixLEG59jR7eRmCDvSCuiSDiuqPPd-2TCdQufuzGrVmlJX4941DjEYW0/s1600/WT_order_4_linear_area_magic_square_S144_170116.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Linear Area Magic Square of order 4 with magic constant S = 144" border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOUFfe5ytOY8D0Tkhl20zupZPm5xmozPUhk14_buM9mStEGJjSKqleyTNm-mLqX3ugGWvOP-1kDU-7QpZMbX3ZixLEG59jR7eRmCDvSCuiSDiuqPPd-2TCdQufuzGrVmlJX4941DjEYW0/s200/WT_order_4_linear_area_magic_square_S144_170116.png" title="Linear Area Magic Square (L-AMS) of Order 4" width="182" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiM47KURN9Hz2R9FJK5925UlNqat6RNdWQgj0iXqpcAzWRTnArTKWgFUyznyNv5qnV_OluIRMvVK-6vxloylMUUt8YP2JB2lx_-iZV2cfLkRVSTp0ig8uafRmxMtlmY_lKzS7FYZXn-TkE/s1600/H-BM_order_4_linear_area_magic_square_S166484_170131.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Linear area magic square (L-AMS) of order 4 with magic constant S = 166464" border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiM47KURN9Hz2R9FJK5925UlNqat6RNdWQgj0iXqpcAzWRTnArTKWgFUyznyNv5qnV_OluIRMvVK-6vxloylMUUt8YP2JB2lx_-iZV2cfLkRVSTp0ig8uafRmxMtlmY_lKzS7FYZXn-TkE/s200/H-BM_order_4_linear_area_magic_square_S166484_170131.png" title="Linear Area Magic Square (L-AMS) of Order 4" width="184" /></a></div><div class="separator" style="clear: both; text-align: center;"><br />
</div></div><div style="text-align: justify;">The linear area magic squares (L-AMS) of order-4 with vertical or horizontal lines have not only interesting geometric properties, but also surprising arithmetic features that are even more exciting. On the 8th February Hans-Bernhard Meyer informed me that the number and the structure of the fourth-order L-AMS with 3 horizontal or vertical lines had been totally clarified by parameterisations with 3 parameters, although this was not yet the case for L-AMS with only 2 horizontal or vertical lines. For full details of the mathematics behind these area magic squares please refer to the related links at the foot of this page.<br />
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On the 12th February 2017, in an e-mail correspondence, I asked Hans-Bernhard Meyer if it was possible to create a L-AMS of order-4 that had a perpendicular intersection of slanted lines. He responded on the 13th February 2017, sending the following L-AMS:<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiKfxwxErb15rcsut4mqSaHvQC6Q4JsEOSl2Oe1KsD-1JTfkJqgp9xuq-fJgxeQ2YJ2FWho2MyQ6ao_atQbYLturIJzP6ThEfjVE6yZrUtAHfccgp19cfXeJPhWbvdliqs-sOK-HOrEuvY/s1600/H-BM_order_4_linear_area_magic_square_S4896_170213.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Linear Area Magic Square of order 4 with perpendicular intersections" border="0" height="218" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiKfxwxErb15rcsut4mqSaHvQC6Q4JsEOSl2Oe1KsD-1JTfkJqgp9xuq-fJgxeQ2YJ2FWho2MyQ6ao_atQbYLturIJzP6ThEfjVE6yZrUtAHfccgp19cfXeJPhWbvdliqs-sOK-HOrEuvY/s200/H-BM_order_4_linear_area_magic_square_S4896_170213.png" title="Linear Area Magic Square (L-AMS) of order 4" width="201" /></a></div><br />
Congratulations to Hans-Bernhard for this interesting square!<br />
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Concerning the possible existence of L-AMS of order-4 without vertical or horizontal lines, on the 12th February 2017 Hans-Bernhard informed me that this question was still quite difficult to resolve.<br />
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Many other types of fourth-order AMS are also possible, and the following squares are area magic interpretations of some of the classical Frénicle squares of order-4:</div><div style="text-align: justify;"><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8ppQ5Wg1MYr8fjCSKsgBGHp0iZhH-7UgMYmmo5nye4hIYANy0mEBGqOL-3kr9hfozWb1yLiezGbpt2KoBe3ZSpUg7qI0HjRkjhWnIG-Bzaarb2bDIHu844fzxCs9k51A5KlhFD3LhXOE/s1600/WT_order_4_area_magic_square_Frenicle_63_170126.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Area Magic Square interpretation of a Frénicle magic square" border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8ppQ5Wg1MYr8fjCSKsgBGHp0iZhH-7UgMYmmo5nye4hIYANy0mEBGqOL-3kr9hfozWb1yLiezGbpt2KoBe3ZSpUg7qI0HjRkjhWnIG-Bzaarb2bDIHu844fzxCs9k51A5KlhFD3LhXOE/s200/WT_order_4_area_magic_square_Frenicle_63_170126.png" title="" width="178" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgLOmYxgVYSZnoRCcGtEyjl9iLWv4I6zRBDPqwNFR5j7k2BLhZbNQ9xC5ifK-SZxPqXur1PzcHltCnX98D8Qkf3fR7bdNcsO3RjpKyovYQXKYvU0s8W0H0ncM0pigW4JsjtMv9vsmuz5WQ/s1600/WW_order_4_area_magic_square_Frenicle_107_170202.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Area magic square interpretation of a classical order-4 Frénicle magic square 107" border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgLOmYxgVYSZnoRCcGtEyjl9iLWv4I6zRBDPqwNFR5j7k2BLhZbNQ9xC5ifK-SZxPqXur1PzcHltCnX98D8Qkf3fR7bdNcsO3RjpKyovYQXKYvU0s8W0H0ncM0pigW4JsjtMv9vsmuz5WQ/s200/WW_order_4_area_magic_square_Frenicle_107_170202.png" title="Area magic square interpretation of Frénicle square 107" width="180" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQ39QU-HtCqguDOWh0LjDiUB8UQg3svjWFrz0DPpr2fpfFYEPgnqYRxiRdgEd2nhGAaUvLVt5NwvpcFU9Jn8HEQ3HjZQeKnK_aY-eHr15EcinKraMTTvETxg80Ex7F6j2aWCRRSRw7Rn4/s1600/WW_order_4_area_magic_square_Frenicle_730_170203.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Area Magic Square Interpretation of the Order-4 Frénicle Magic Square 730" border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQ39QU-HtCqguDOWh0LjDiUB8UQg3svjWFrz0DPpr2fpfFYEPgnqYRxiRdgEd2nhGAaUvLVt5NwvpcFU9Jn8HEQ3HjZQeKnK_aY-eHr15EcinKraMTTvETxg80Ex7F6j2aWCRRSRw7Rn4/s200/WW_order_4_area_magic_square_Frenicle_730_170203.png" title="Area Magic Square Interpretation of Frénicle Magic Square 730" width="181" /></a></div></div><br />
<h3 style="text-align: justify;"><u>Related links</u></h3><div style="text-align: justify;"></div><br />
<div style="text-align: justify;">Since the 3rd February 2017, full details of the findings of <a href="http://www.trump.de/magic-squares/" target="_blank">Walter Trump</a> can be found in the chapter <a href="http://www.trump.de/magic-squares/area-magic/index.html" target="_blank">"Area Magic Squares"</a> of his website: Notes on Magic Squares and Cubes.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Since the 25th January 2017, full details of the findings of <a href="http://www.hbmeyer.de/index.html" target="_blank">Hans-Bernhard Meyer</a> can be found in the article <a href="http://www.hbmeyer.de/backtrack/area/index.html" target="_blank">"Observations on 4x4 Area Magic Squares with Vertical Lines"</a> of his website: Math'-pages.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Since the 25th January 2017, <a href="https://carresmagiques.blogspot.com/2020/04/area-magic-squares-of-order-6.html" target="_blank">"Area Magic Squares of Order-6"</a> relates the first findings of area magic squares of the sixth-order.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Since the 13th January 2017, <a href="https://carresmagiques.blogspot.com/2020/04/area-magic-squares-and-tori-of-order-3.html" target="_blank">"Area Magic Squares and Tori of Order-3"</a> relates the first findings of area magic squares of the third-order. <br />
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In the N° 487 2018 May issue of <a href="https://www.pourlascience.fr/sd/mathematiques/les-carres-magiques-daires-13295.php" rel="" target="_blank">"Pour La Science"</a> (the French edition of Scientific American), Professor Jean-Paul Delahaye has written an article entitled <a href="https://issuu.com/pourlascience/docs/pls_0487_pdf_apps/80" rel="" target="_blank">"Les Carrés Magiques d'Aires."</a><br />
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In the December 2018 issue of <a href="https://www.spektrum.de/magazin/flaechenmagische-quadrate/1603760" rel="" target="_blank">"Spektrum der Wissenschaft"</a> (a Springer Nature journal, and the German edition of Scientific American), Professor Jean-Paul Delahaye has written an article entitled <a href="https://www.spektrum.de/magazin/flaechenmagische-quadrate/1603760" rel="" target="_blank">"FLÄCHENMAGISCHE QUADRATE."</a></div><div style="text-align: justify;"> <br /><div style="text-align: justify;">
On the 21st May 2021, <a href="https://www.researchgate.net/profile/Yoshiaki-Araki" target="_blank">Yoshiaki Araki</a> (面積魔方陣がテセレーションみたいな件
@alytile) tweeted several order-4 and order-3 solutions in <a href="https://twitter.com/alytile/status/1395611974390542337/photo/1" target="_blank">a polyomino area magic square thread</a>. These included (amongst others) an order-4 example constructed with 16 assemblies of 5 to 20 dominoes. For more information on polyomino area magic squares please check the links at the end of the article <a href="https://carresmagiques.blogspot.com/2020/04/area-magic-squares-and-tori-of-order-3.html" target="_blank">"Area Magic Squares of Order-3."</a></div><div style="text-align: justify;"> </div><div style="text-align: justify;">Since the 22nd June 2021, <a href="https://inderjtaneja.com/" target="_blank">Inder Taneja</a> has published a paper entitled <a href="https://zenodo.org/record/5009224" target="_blank">"Creative Magic Squares: Area Representations"</a> in which he explores polyomino area magic using perfect square magic sums.</div><div style="text-align: justify;"> </div><div style="text-align: justify;">A new post on <a href="https://carresmagiques.blogspot.com/2022/06/polyomino-area-magic-tori.html" target="_blank">"Polyomino Area Magic Tori"</a> can be found in these pages since the 7th June 2022.</div></div>
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William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-85084846245684643982017-01-25T13:21:00.006+01:002023-06-19T23:08:33.814+02:00Area Magic Squares of Order-6<a href="https://blogger.googleusercontent.com/img/a/AVvXsEj1YHUinWNl82nEDVsTXqYxUn_h3waO0_6v4XXBrZpPk6y1spEF1FxB0uOACcCxk3H4N4hl9B_Tiw9dVqUlF92nYPs8ctquMmknlo8tutb3uI3tPt2WOK5F5m-JQAevoIRhYTf3Xvozw7Q2JTjZKl2EdBswp0TS7P8rmHnXgxk1hm4lBlFhYuWr0gid=s7908" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="4144" data-original-width="7908" height="168" src="https://blogger.googleusercontent.com/img/a/AVvXsEj1YHUinWNl82nEDVsTXqYxUn_h3waO0_6v4XXBrZpPk6y1spEF1FxB0uOACcCxk3H4N4hl9B_Tiw9dVqUlF92nYPs8ctquMmknlo8tutb3uI3tPt2WOK5F5m-JQAevoIRhYTf3Xvozw7Q2JTjZKl2EdBswp0TS7P8rmHnXgxk1hm4lBlFhYuWr0gid=s320" style="display: none;" width="320" /></a><table></table>
<div style="text-align: justify;">After my previous post "<a href="https://carresmagiques.blogspot.fr/2017/01/area-magic-squares-and-tori-of-order-3.html" target="_blank">Area Magic Squares and Tori of Order-3</a>," <a href="http://www.trump.de/magic-squares/" rel="nofollow" target="_blank">Walter Trump</a> continued his computer research of the linear area magic squares of order-4, now joined in this venture by a fellow mathematician and programmer <a href="http://www.hbmeyer.de/magic.htm" rel="nofollow" target="_blank">Hans-Bernhard Meyer</a>.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Having already some insight into the linear area magic squares of the odd-order-3 and of the doubly-even-order-4, it was tempting to search for a singly-even-order example. I therefore decided to do some exploring, and on the 22nd January 2017, I found this first linear area magic square of order-6:<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjfQx3tGiPS0Ir2lS69-1-f3R158DsnJSlXALO5BmrN06zEIsH7MMt8YP1BOPokN7XKGw2dsoBzR6tWBYu__in0Y0GFClvB1R0SjcPTXvF8ooLvjA69SWhsDhmTLnJTHVyV2fUphKntHWI/s1600/WW_order_6_linear_area_magic_square_170122_colour_grade_og.png" style="margin-left: 1em; margin-right: 1em;"><img alt="First Linear Area Magic Square of Order-6 with magic sum S=1296" border="0" data-original-height="1296" data-original-width="1600" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjfQx3tGiPS0Ir2lS69-1-f3R158DsnJSlXALO5BmrN06zEIsH7MMt8YP1BOPokN7XKGw2dsoBzR6tWBYu__in0Y0GFClvB1R0SjcPTXvF8ooLvjA69SWhsDhmTLnJTHVyV2fUphKntHWI/s400/WW_order_6_linear_area_magic_square_170122_colour_grade_og.png" title="" width="495" /></a></div></div><div style="text-align: justify;"><br />
For the area magic square shown above, the magic constant of each row, column and main diagonal is 1296 (6<span style="font-size: small;"><sup>4</sup></span>). The total areas are therefore 7776 (6<span style="font-size: small;"><sup>5</sup></span>). The mean number of each row, column and main diagonal is 216 (6<span style="font-size: small;"><sup>3</sup></span>). The last digits of the first and last numbers of the horizontal non-parallel rows are either 1 for odd number sequences, or 6 for even number sequences. Please note that the area cell 41 is not a triangle, but a trapezium (or trapezoid) like all the other cells. For those amongst you who may be interested in the mathematical construction, Hans-Bernhard Meyer has since very kindly produced the following parameterisation:</div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6iaQIm920H9ZYbp4cjqiEHCv2H4n_PnbqL7g-GPhIPkuY7fdHlcyLQu0xaX5Kz-UauuGEA_XtqDyJ7CJhVV3Zk_OUB2z2-ah1D2ma1s74Ye992Gy-vG9lARoLv0d7P1dT4o0zI3u-GFk/s1600/Para6x6_H-B_Meyer.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Parameters of a linear area magic square of order 6" border="0" height="197" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6iaQIm920H9ZYbp4cjqiEHCv2H4n_PnbqL7g-GPhIPkuY7fdHlcyLQu0xaX5Kz-UauuGEA_XtqDyJ7CJhVV3Zk_OUB2z2-ah1D2ma1s74Ye992Gy-vG9lARoLv0d7P1dT4o0zI3u-GFk/s640/Para6x6_H-B_Meyer.png" title="" width="518" /></a></div><br />
<div style="text-align: justify;">From then on using a computer program to find many more examples, on the 26th January 2017, Hans-Bernhard Meyer drew to my attention a new linear area magic square with not only parallel vertical lines, but also a central horizontal line. He kindly authorised me to publish this example illustrated below:</div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVSY2Ub_JMjL1J6RkaJltFM8vUWb8jqSAPda7UIcHUWUZ01-KTFwEadPdxkR_k5dLFT1RQwDs5t98iM0RBI5w04bYLYXqUrwVBAHzNbKEuAp4JibcNkBimWBUVhH0zmivvil2JA_WlMjc/s1600/H-B_M_order_6_linear_area_magic_square_170126.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Linear area magic square of order 6" border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVSY2Ub_JMjL1J6RkaJltFM8vUWb8jqSAPda7UIcHUWUZ01-KTFwEadPdxkR_k5dLFT1RQwDs5t98iM0RBI5w04bYLYXqUrwVBAHzNbKEuAp4JibcNkBimWBUVhH0zmivvil2JA_WlMjc/s320/H-B_M_order_6_linear_area_magic_square_170126.png" title="" width="303" /></a></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The magic constant of this linear area magic square (L-AMS) is 474, and the total areas are 2,844. The last digits of the first and last numbers of the non-parallel rows are either 4 for the even number sequences, or 9 for the odd number sequences. I noticed that in addition to the central horizontal line, there was also a pair of broken magic diagonals which would enable an easy transformation, as illustrated below:<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgx4qzENXCFlAWCPbJgvzJLUKPu99g_zY8rT7ikbZRgaYlyaW6yaezh2HPNtICBM1K7MLkRFIVjosoG1O89Fw8Sd4g5YuNJPrvPW2JliOaEiZMRbN7Ugk984tdKbUTxOFi9XN_LmiZ1oZU/s1600/WW_order_6_linear_area_magic_square_170127_trans_2_sq_H-B_M.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Area Magic Square of Order-6 after transformation, with magic sum S=474" border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgx4qzENXCFlAWCPbJgvzJLUKPu99g_zY8rT7ikbZRgaYlyaW6yaezh2HPNtICBM1K7MLkRFIVjosoG1O89Fw8Sd4g5YuNJPrvPW2JliOaEiZMRbN7Ugk984tdKbUTxOFi9XN_LmiZ1oZU/s320/WW_order_6_linear_area_magic_square_170127_trans_2_sq_H-B_M.png" title="Area Magic Square of Order-6 after transformation" width="302" /></a></div></div><br />
<div style="text-align: justify;">It can be seen that these are two essentially different L-AMS viewpoints of a same area magic cylinder. Please note that there are also another four <i>area semi-magic parallelograms</i> displayed on this cylinder (with cells 44, 124, 144, or 19 in their top left corners).<br />
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On the 29th January 2017, Hans-Bernhard Meyer informed me that the following can be proved:<br />
Every 6x6 L-AMS with magic sum S and horizontal centre line has the property:<br />
x04+x11+x18+x19+x26+x33 = x03+x08+x13+x24+x29+x34 = S<br />
and conversely, every 6x6 L-AMS with magic sum S and <br />
x04+x11+x18+x19+x26+x33 = x03+x08+x13+x24+x29+x34 = S<br />
has a horizontal centre line.<br />
He stated that there are many examples of such L-AMS and strongly supposed that the example illustrated above had the lowest possible magic sum. He was able to confirm that examples with 2 horizontal lines do not exist.<br />
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On the same day, Hans-Bernhard also informed me that in the order-6, the L-AMS with the lowest possible magic sum had a magic constant of 402. He had found that there were several of these L-AMS, and kindly sent me details of an example, which I have illustrated below:<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhVUncDrVqeivWKrfyEA4o5sM-nmO-Ao5k6RzyrTQWyzel75XFIAjvIAX5n69Oc9gKOI-GjxW7JviQ7iCfndBOjnusEPlEwB6cQWLgj6crTNotjg_udQC93vy1N7Q3WNaEIctkQm2MFYjs/s1600/H-B_M_smallest_order_6_linear_area_magic_square_170129.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Linear area magic square of order 6" border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhVUncDrVqeivWKrfyEA4o5sM-nmO-Ao5k6RzyrTQWyzel75XFIAjvIAX5n69Oc9gKOI-GjxW7JviQ7iCfndBOjnusEPlEwB6cQWLgj6crTNotjg_udQC93vy1N7Q3WNaEIctkQm2MFYjs/s320/H-B_M_smallest_order_6_linear_area_magic_square_170129.png" title="" width="302" /></a></div><br />
</div><div style="text-align: justify;">The total areas of this square are 2,412. The last digits of the first and last numbers of the non-parallel rows are either 2 for the even number sequences, or 7 for the odd number sequences. The even number sequence of the bottom row begins with 12, which Hans-Bernhard informs me is the lowest possible vertex area for L-AMS (linear area magic squares) of order-6.<br />
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</div><div style="text-align: justify;">These are only the first of an infinite number of examples that remain to be discovered, and I therefore expect to be regularly publishing updates to this post!<br />
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<h3><u>Related links</u></h3><br />
A former post <a href="https://carresmagiques.blogspot.fr/2017/01/area-magic-squares-and-tori-of-order-3.html" target="_blank">Area Magic Squares and Tori of Order-3</a> can be found in these pages since the 13th January 2017. <br />
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On the 25th January 2017, <a href="http://www.hbmeyer.de/index.html" rel="nofollow" target="_blank">Hans-Bernhard Meyer</a> published an article entitled <a href="http://www.hbmeyer.de/backtrack/area/index.html" target="_blank">Observations on 4x4 Area Magic Squares with vertical lines</a> in his website: Math'-pages.<br />
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On the 3rd February 2017, <a href="http://www.trump.de/magic-squares/" rel="nofollow" target="_blank">Walter Trump</a> published a chapter entitled <a href="http://www.trump.de/magic-squares/area-magic/index.html" target="_blank">Area Magic Squares</a> in his website: Notes on Magic Squares. This chapter includes many analyses and examples of area magic squares of the third and fourth-orders.<br />
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Since the 8th February 2017, <a href="https://carresmagiques.blogspot.fr/2017/02/area-magic-squares-of-order-4.html" target="_blank">"Area Magic Squares of Order-4"</a> relates the first findings of area magic squares of the fourth-order.<br />
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In the N° 487 2018 May issue of <a href="https://www.pourlascience.fr/sd/mathematiques/les-carres-magiques-daires-13295.php" rel="nofollow" target="_blank">"Pour La Science"</a> (the French edition of Scientific American), Professor Jean-Paul Delahaye has written an article entitled <a href="https://issuu.com/pourlascience/docs/pls_0487_pdf_apps/80" rel="nofollow" target="_blank">"Les Carrés Magiques d'Aires."</a><br />
<br />
In the December 2018 issue of <a href="https://www.spektrum.de/magazin/flaechenmagische-quadrate/1603760" rel="nofollow" target="_blank">"Spektrum der Wissenschaft"</a> (a Springer Nature journal, and the German edition of Scientific American), Professor Jean-Paul Delahaye has written an article entitled <a href="https://www.spektrum.de/magazin/flaechenmagische-quadrate/1603760" rel="nofollow" target="_blank">"FLÄCHENMAGISCHE QUADRATE."</a></div><div style="text-align: justify;"> </div><div style="text-align: justify;">On the 21st May 2021, <a href="https://www.researchgate.net/profile/Yoshiaki-Araki" target="_blank">Yoshiaki Araki</a> (面積魔方陣がテセレーションみたいな件
@alytile) tweeted several order-4 and order-3 solutions in <a href="https://twitter.com/alytile/status/1395611974390542337/photo/1" target="_blank">a polyomino area magic square thread</a>.
These included (amongst others) an order-4 example constructed with 16
assemblies of 5 to 20 dominoes. For more information on polyomino area
magic squares please check the links at the end of the article <a href="https://carresmagiques.blogspot.com/2020/04/area-magic-squares-and-tori-of-order-3.html" target="_blank">"Area Magic Squares of Order-3."</a></div><div style="text-align: justify;"> </div><div style="text-align: justify;">Since the 22nd June 2021, <a href="https://inderjtaneja.com/" target="_blank">Inder Taneja</a> has published a paper entitled <a href="https://zenodo.org/record/5009224" target="_blank">"Creative Magic Squares: Area Representations"</a> in which he explores polyomino area magic using perfect square magic sums.</div><div style="text-align: justify;"> </div><div style="text-align: justify;"> A new post on <a href="https://carresmagiques.blogspot.com/2022/06/polyomino-area-magic-tori.html" target="_blank">"Polyomino Area Magic Tori"</a> can be found in these pages since the 7th June 2022.</div></div>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-68745268764386548982017-01-13T12:14:00.006+01:002023-06-19T23:09:29.130+02:00Area Magic Squares and Tori of Order-3<div style="text-align: justify;">
In December 2016 I made a sketch design of an area magic square to illustrate a seasonal greetings card for 2017. Using the traditional order-3 magic square, I attempted to use continuous straight lines for the area cell borders. I quickly realised that such an assembly was impossible to achieve, but that with approximate areas I could nevertheless make a pleasing graphic pattern:
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQoTGSVScTQATijb1Vs9RHW9h3Q6YeneXtSgiybbfdShE65vsly7uen4OS9igMoh3iV8MgSQAUxeVYj31ymLRSW6y2nsTsf1psACe19Txk5fyVm2GeTwvIrEHPWOMbv3fV0iLO08wMFuY/s1600/Best_wishes_WW_2017_first_area_magic_square.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Area magic square design for 2017 seasonal greetings card, using approximate areas" border="0" data-original-height="838" data-original-width="1600" height="208" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQoTGSVScTQATijb1Vs9RHW9h3Q6YeneXtSgiybbfdShE65vsly7uen4OS9igMoh3iV8MgSQAUxeVYj31ymLRSW6y2nsTsf1psACe19Txk5fyVm2GeTwvIrEHPWOMbv3fV0iLO08wMFuY/s400/Best_wishes_WW_2017_first_area_magic_square.png" title="" width="400" /></a>
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Sending this image with my best wishes to a circle of magic square enthusiasts on the 30th December 2016, I added the following postscript: "The areas are approximate, and I don't know if it is possible to obtain the correct areas with 2 vertically slanted straight lines through the square. Perhaps someone will be able to work this out in 2017?"</div>
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<a href="https://en.wikipedia.org/wiki/Lee_Sallows" rel="" target="_blank">Lee Sallows</a> was the first to respond on the 4th and 5th January 2017, proposing an approach based on his previous work on geomagic squares. Developing the ideas that can be found in the figure 4.1 on page 5 of his book <i>"Geometric Magic Squares: A Challenging New Twist Using Colored Shapes Instead of Numbers,"</i> his area square is illustrated below: </div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHZguptPjM6cRUOUjIWPqYRJrfeyZ23fDS3DwSBuT0z8qfFdjS30uUn5pPvSQ8jLJYtXQO6-mg-QKnw816zbdcOICtSGT6wweiOjgkStuGJMNZkt2QlYBxWj5qgAq7vB68Rm7U48dehgM/s1600/WilliamWalk4.png" style="margin-left: auto; margin-right: auto;"><img alt="Area square by Lee Sallows" border="0" height="170" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHZguptPjM6cRUOUjIWPqYRJrfeyZ23fDS3DwSBuT0z8qfFdjS30uUn5pPvSQ8jLJYtXQO6-mg-QKnw816zbdcOICtSGT6wweiOjgkStuGJMNZkt2QlYBxWj5qgAq7vB68Rm7U48dehgM/s200/WilliamWalk4.png" title="" width="168" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Area square by Lee Sallows</span></td></tr>
</tbody></table>
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Lee Sallows points out that, when comparing the initial square of his book with this new puzzle square, "in many (but not all) cases adjacent piece outlines have been made to complement each other. For every gain in area at one position there is an identical loss of area at another. In this way the areas of all 9 pieces remain as they were, so that the square remains a magical dissection." Thank you for your work Lee! I particularly like your puzzle solution.</div>
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Meanwhile, I was wondering if a solution could be found for a third-order area magic torus, that is to say, one where the area cell intersections would meet correctly when wrapped. With this purpose in mind I set the following new rules for myself:</div>
<div style="text-align: justify;">
1/ Each cell will have an area that corresponds with its number from 1 to 9. The total areas will therefore be 45.</div>
<div style="text-align: justify;">
2/ The connections between the cells will remain unchanged, but as these cells will be of different sizes, the resulting latitudes, longitudes and diagonals will not necessarily be straight lines. The initially square cells will become regular or irregular quadrilaterals, (excluding complex quadrilaterals).</div>
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3/ The distances measured orthogonally between opposite sides of the resulting magic or semi-magic square viewpoints will always be √45, (the circumferences of the magic torus).</div>
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This third rule took into account the flattened square that we are accustomed to looking at, but it also implied that the torus would degenerate into a sphere... With these new constraints, on the 6th January 2017 I was able to come up with the area magic torus illustrated below:</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhe4OuAdQpzpVIGczacafvQCfoz4sxNTOcZhiyqLnApZhUvz4Y85tKm5uppIPB3SF1X8XiN-0hNfvl27201hLL-UCI6ZAJNym9d2sKC3ydk6WNN9PSACcROgALuAnAfCuQes55ZAwBcVWQ/s1600/Best_wishes_WW_2017_extended_first_edition_area_magic_torus.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="Area Magic Torus of Order-3 with Nine Viewpoints, in a 2017 Seasonal Greetings Card Design" border="0" height="395" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhe4OuAdQpzpVIGczacafvQCfoz4sxNTOcZhiyqLnApZhUvz4Y85tKm5uppIPB3SF1X8XiN-0hNfvl27201hLL-UCI6ZAJNym9d2sKC3ydk6WNN9PSACcROgALuAnAfCuQes55ZAwBcVWQ/s400/Best_wishes_WW_2017_extended_first_edition_area_magic_torus.jpg" title="Area Magic Torus of Order-3 in a 2017 Seasonal Greetings Card Design" width="400" /></a></div>
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These extended best wishes, expressed through the complete set of third-order magic and semi-magic squares, include messages that reflect the multiple nationalities of the members of the magic square circle. The magic square viewpoint of the torus is placed at the top left. The patterns still need adjusting in order to achieve the correct areas, but as there is more flexibility, I am fairly confident that at least one accurate solution can be found.</div>
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On the 6th January 2017 <a href="https://en.wikipedia.org/wiki/Walter_Trump" rel="" target="_blank">Walter Trump</a> also sent us a new area magic design that used 4 continuous straight dissection lines. Although this schema could not be adapted to the number sequence 1 to 9, it was area magic:</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0bqEazZ9E0sFLwLNqos9Cu24s7W51aVlltGQHzoxoZOlvusCOXkJjmSdwYKOnn9rwoQwyQDwAAPzmKSdeDoHF17cvk6uzUVvQN-8nX2-3rwPsn6swtjAbKuUMN8Jg5HIDIMJGlwz9Ggg/s1600/magic-square.png" style="margin-left: auto; margin-right: auto;"><img alt="Area magic schema for order 3" border="0" height="197" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0bqEazZ9E0sFLwLNqos9Cu24s7W51aVlltGQHzoxoZOlvusCOXkJjmSdwYKOnn9rwoQwyQDwAAPzmKSdeDoHF17cvk6uzUVvQN-8nX2-3rwPsn6swtjAbKuUMN8Jg5HIDIMJGlwz9Ggg/s200/magic-square.png" title="" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Area Magic Schema by Walter Trump</span></td></tr>
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<a href="https://inderjtaneja.com/category/magic-squares/" rel="" target="_blank">Inder Jeet Taneja</a> then suggested that the problem with the sequence 1 to 9 was that the total areas did not add up to a perfect square area. He proposed that instead of using the numbers 1 to 9, perhaps we should try using the numbers 5 + 6 + ... + 13 = 81 = 9² ?</div>
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On the same day, following Inder's suggestion, Walter Trump amazed us all with this first third-order linear area magic square! :</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-iiVfT92aC1yuTmxiKoYP1D_XmUg3F0hxrx-fZZnwf1SO_RQ0SpMCV336IxwC1IUHeZs_p9f4XDwrs_G1JZZ1Exh3M9qofiETJudD1b0nd2SbOmAqgjma9YKZqcr3NQSgb75tUVJSHno/s1600/Trump_Walkington_Taneja_linear_area_magic_square_170106.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="First linear area magic square of order 3" border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-iiVfT92aC1yuTmxiKoYP1D_XmUg3F0hxrx-fZZnwf1SO_RQ0SpMCV336IxwC1IUHeZs_p9f4XDwrs_G1JZZ1Exh3M9qofiETJudD1b0nd2SbOmAqgjma9YKZqcr3NQSgb75tUVJSHno/s200/Trump_Walkington_Taneja_linear_area_magic_square_170106.jpg" title="" width="191" /></a></div>
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Bravo Walter for your achievement following Inder's suggestion! I hardly dared to believe that such a simple area pattern could produce a magic square!</div>
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Having other commitments to honour, Walter Trump then requested that somebody else searched for solutions using lower sequences. No other volunteers came forward, so I decided to look for myself, and came up with this second linear area magic square of the third-order using the sequence 3 to 11:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJfTbpkSj5_u-Tfx3jqBlKJ70JG0-D_TcCP-vcMCuIZgWvL3otqGkkfjirHiejr-XLjJQcpcPwbHZvEb-gfm_PePhO6-N09hV-0nfhW72PgmzMuDEw8DPRf17HeRmfHr1WXrL1k6QjxPo/s1600/Walkington_linear_area_magic_square_2_170108_colours.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="Area magic square of order 3 with approximate dimensions" border="0" height="266" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJfTbpkSj5_u-Tfx3jqBlKJ70JG0-D_TcCP-vcMCuIZgWvL3otqGkkfjirHiejr-XLjJQcpcPwbHZvEb-gfm_PePhO6-N09hV-0nfhW72PgmzMuDEw8DPRf17HeRmfHr1WXrL1k6QjxPo/s320/Walkington_linear_area_magic_square_2_170108_colours.jpg" title="" width="227" /></a></div>
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As I am not a programmer, I used Autocad to construct this linear area magic square manually. The areas of this provisional square are therefore only accurate up to two decimal places, before computer verification and area optimisation.</div>
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In the meantime Walter Trump continued writing a computer program to handle the equations and search iteratively for solutions. This was able to give orthogonal coordinates having at least 14 decimals after the commas. At first unable to solve the non-linear equations explicitly, Walter progressively improved his approach, and on the 8th January 2017 he sent us a message stating that for some sequences there were two solutions, and that the lowest number sequence ranged from 2 to 10!</div>
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On the 10th January 2017, Walter Trump created an algorithm for <a href="https://drive.google.com/file/d/0B7bucUs2xUSVQi1TVTl2cVA2R1E/view?usp=sharing" rel="" target="_blank">"Third-Order Linear Area Magic,"</a> which he has kindly authorised me to publish below. This explains the method of construction and gives the reason why two solutions exist for most, but not all of the sequences studied:</div>
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<iframe height="710px" src="https://docs.google.com/viewer?srcid=0B7bucUs2xUSVQi1TVTl2cVA2R1E&pid=explorer&efh=false&a=v&chrome=false&embedded=true" width="518px"></iframe><br />
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Using the coordinates generated by Walter Trump's computer program, both solutions of the 5 lowest sequences of the third-order linear area magic squares are illustrated in square form below. It will be seen that the 1 to 9 sequence fails, and the linear area magic squares are only possible from the sequence 2 to 10 upwards (when the continuous straight dissection lines produce no more than 4 intersections inside the squares):</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-LLAZb0RCazgPEXhkjtBpJpVMfT_e80mcf3PJPHvYqrVstY3ScowF-DlVRPmN-EgHJ907R14-FFJYPW7G6McxoSc-ZvfUu4srTczXelu4dTIRN9MMqPJjYcP-ocVutV2lB04zxZdIrkM/s1600/order_3_linear_area_magic_square_fails_seq_1-9_v1.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 3 area magic square solution 1 sequence 1 to 9" border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-LLAZb0RCazgPEXhkjtBpJpVMfT_e80mcf3PJPHvYqrVstY3ScowF-DlVRPmN-EgHJ907R14-FFJYPW7G6McxoSc-ZvfUu4srTczXelu4dTIRN9MMqPJjYcP-ocVutV2lB04zxZdIrkM/s200/order_3_linear_area_magic_square_fails_seq_1-9_v1.jpg" title="" width="175" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWu7mlXjzsoYzws5BNPuGbU7qUsfzEBnoEPjq-cRyat0cYrp5G0wuRzeJigSOZTCkCo9_1czRPOHgbUYgUxKdtpUZREKm4hJ1mLBkJH7-DZ6Msj4WbvtRq6F3qTe8awnTEnJDTf1uUC_s/s1600/order_3_linear_area_magic_square_fails_seq_1-9_v2.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="Order 3 area magic square solution 2 sequence 1 to 9" border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWu7mlXjzsoYzws5BNPuGbU7qUsfzEBnoEPjq-cRyat0cYrp5G0wuRzeJigSOZTCkCo9_1czRPOHgbUYgUxKdtpUZREKm4hJ1mLBkJH7-DZ6Msj4WbvtRq6F3qTe8awnTEnJDTf1uUC_s/s200/order_3_linear_area_magic_square_fails_seq_1-9_v2.jpg" title="" width="173" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkyQbywZBSCVsepnRXaMej0O_0hvsptJdK6tljRHyNjbgkSF9YhrUDOul3vk3DqD7V0ghSLHWmSiu0HqRuufsHAUVKLtOXjV9xW4u22k8PWdAQS8fjBk0M-CsLA8rRPxJjNcmhZxhwrO4/s1600/order_3_linear_area_magic_square_fails_seq_2-10_v1.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 3 area magic square solution 1 sequence 2 to 10" border="0" height="219" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkyQbywZBSCVsepnRXaMej0O_0hvsptJdK6tljRHyNjbgkSF9YhrUDOul3vk3DqD7V0ghSLHWmSiu0HqRuufsHAUVKLtOXjV9xW4u22k8PWdAQS8fjBk0M-CsLA8rRPxJjNcmhZxhwrO4/s200/order_3_linear_area_magic_square_fails_seq_2-10_v1.jpg" title="" width="190" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKYQ9rM1D3BBa9vPuQyQ12N1QDdlHxaKvmM2N0z8DOSXA69FvS6DHUmqVyrcWXGarwEPUHNdQXdU26QJM2xHo2rZ62tdzgNhjiENui9ft_BItrBH1Wrn-H2-waeALzasljYpHfWDLFNMY/s1600/order_3_linear_area_magic_square_seq_2-10_v2.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 3 area magic square solution 2 sequence 2 to 10" border="0" height="219" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKYQ9rM1D3BBa9vPuQyQ12N1QDdlHxaKvmM2N0z8DOSXA69FvS6DHUmqVyrcWXGarwEPUHNdQXdU26QJM2xHo2rZ62tdzgNhjiENui9ft_BItrBH1Wrn-H2-waeALzasljYpHfWDLFNMY/s200/order_3_linear_area_magic_square_seq_2-10_v2.jpg" title="" width="190" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPsw8uS4FpoYrZSb421maaFc9TS1aWCGwYUXq999Gz8I0q-Mp9ixpctzbwk6Db96PVMJZ8jEfrObmfssfcoLa6Jbi5qVoTikvdT6xj_2r8KdbcQBW5-RZef5LkP_WjyjQx1-tZ2fQ49uY/s1600/order_3_linear_area_magic_square_seq_3-11_v1.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 3 area magic square solution 1 sequence 3 to 11" border="0" height="237" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPsw8uS4FpoYrZSb421maaFc9TS1aWCGwYUXq999Gz8I0q-Mp9ixpctzbwk6Db96PVMJZ8jEfrObmfssfcoLa6Jbi5qVoTikvdT6xj_2r8KdbcQBW5-RZef5LkP_WjyjQx1-tZ2fQ49uY/s200/order_3_linear_area_magic_square_seq_3-11_v1.jpg" title="" width="209" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEE30Ol8buBc2_aUiIr6GR1UQSdVul7NNscU7tJBXJI1A5HXi3fcIeBmyQdBShDucm4FwGF5h8oZqcZW3e5g8YhXXTEb8GilZ-J1tm5ndjodN6LZ2IPj-dfpBr3u3vaHdtu20MlNwdj8k/s1600/order_3_linear_area_magic_square_seq_3-11_v2.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 3 area magic square solution 2 sequence 3 to 11" border="0" height="237" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEE30Ol8buBc2_aUiIr6GR1UQSdVul7NNscU7tJBXJI1A5HXi3fcIeBmyQdBShDucm4FwGF5h8oZqcZW3e5g8YhXXTEb8GilZ-J1tm5ndjodN6LZ2IPj-dfpBr3u3vaHdtu20MlNwdj8k/s200/order_3_linear_area_magic_square_seq_3-11_v2.jpg" title="" width="210" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgukFd0bru7iG3BiDhiR4hMd1cLECarICRNCrplDZOGPloQMZ2fCdDjobyO9fhs6wPOHVn5qZcWBS4YTgNnEVlMGqrI-b0WcP_40S88dpuSEZ0uw68d4mAyuFG52LbpINOuyVGDCoiOgaU/s1600/order_3_linear_area_magic_square_seq_4-12_v1.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 3 area magic square solution 1 sequence 4 to 12" border="0" height="253" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgukFd0bru7iG3BiDhiR4hMd1cLECarICRNCrplDZOGPloQMZ2fCdDjobyO9fhs6wPOHVn5qZcWBS4YTgNnEVlMGqrI-b0WcP_40S88dpuSEZ0uw68d4mAyuFG52LbpINOuyVGDCoiOgaU/s200/order_3_linear_area_magic_square_seq_4-12_v1.jpg" title="" width="226" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-5soTC-G7MKiK6IaWWj2OUHTgT-y3XCg43Lif8SQFFr_fZlEO2I3Yp0jHgajTN9QQKtkFWp3WVQ173li-L38K1hxOFmFROXWIccanD1uZzhkM07QwUqDeHidRQ8bVV25ZdC0lv1HWYDg/s1600/order_3_linear_area_magic_square_seq_4-12_v2.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 3 area magic square solution 2 sequence 4 to 12" border="0" height="253" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-5soTC-G7MKiK6IaWWj2OUHTgT-y3XCg43Lif8SQFFr_fZlEO2I3Yp0jHgajTN9QQKtkFWp3WVQ173li-L38K1hxOFmFROXWIccanD1uZzhkM07QwUqDeHidRQ8bVV25ZdC0lv1HWYDg/s200/order_3_linear_area_magic_square_seq_4-12_v2.jpg" title="" width="228" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8zoJpczWPp5rDV60MPhOyXoE6iRailfBjHGnDnTbjcNcFokmZcCtCsB9bFVXbyRsVpAopQR3WQTfjTKITGkB715u4aHpdsIQWGkSYDp6TBRG4OZBSirBlRy_WVwbymxzxOsLHHv4BFao/s1600/order_3_linear_area_magic_square_seq_5-13_v1.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 3 area magic square solution 1 sequence 5 to 13" border="0" height="268" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8zoJpczWPp5rDV60MPhOyXoE6iRailfBjHGnDnTbjcNcFokmZcCtCsB9bFVXbyRsVpAopQR3WQTfjTKITGkB715u4aHpdsIQWGkSYDp6TBRG4OZBSirBlRy_WVwbymxzxOsLHHv4BFao/s200/order_3_linear_area_magic_square_seq_5-13_v1.jpg" title="" width="238" /></a></div>
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During this time my first question concerning the sequence 1 to 9 remained unanswered. So, on the 9th January 2017, I created the first area magic square that used the numbers of the classical magic square of order-3, as illustrated below:</div>
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<img alt="Mont-Saint-Michel design for an area magic square interpretation of the classical order-3 magic square" border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_VnqpPMn2RhWz1JN3CxjmA19Hisawz0bokhGN38e-HTXnxp31pRLagPkwFiuN_RaNwAb7qU2T93j1rKY5nYHK_K6ZyP1iWX5Cjv88GO0NHBZscQYaaKjf1_v9R9bGddvBCUXTtXPXCWY/s200/Walkington_area_magic_square_3_170109.jpg" title="Area Magic Square of order-3" width="185" /></div>
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More recreational than mathematical, this <a href="https://upload.wikimedia.org/wikipedia/commons/7/78/Mont-Saint-Michel_vu_du_ciel.jpg" rel="" target="_blank">"Mont Saint Michel"</a> area magic square demonstrates that it is possible to use 2 continuous straight dissection lines - thus resolving the initial 2017 greetings card challenge. The design is an area magic square, because all of the cells are quadrilaterals (even if near triangular for the area 1), and all of their connections are preserved.</div>
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Inder Taneja has since followed up on his initial suggestions for perfect square sequences. On the 11th February 2017 he published some very interesting results in his new paper <a href="https://rgmia.org/papers/v20/v20a11.pdf" rel="" target="_blank">"Magic Squares with Perfect Square Number Sums."</a></div>
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This is an ongoing story, and there will probably be new developments in the near future. Apart from Inder Taneja, Lee Sallows and Walter Trump who I have already mentioned, I also wish to thank the other participants: These include <a href="http://www.knechtmagicsquare.paulscomputing.com/" rel="" target="_blank">Craig Knecht</a> for his kind encouragements, <a href="http://www.multimagie.com/AmelaUHIMS.pdf" rel="" target="_blank">Miguel Angel Amela</a> for his encouragements and suggestions concerning accuracy, <a href="http://magictesseract.com/order-4_squares" rel="" target="_blank">Dwane Campbell</a> for his encouragements and suggestions, and last but not least, <a href="http://www.gaspalou.fr/magic-squares/" rel="" target="_blank">Francis Gaspalou</a> for his encouragements and interventions: For the area magic squares of the third-order, Francis Gaspalou wrote the equations of the 4 straight lines using 4 parameters which were the 4 slopes of those lines. He found the exact conditions which had to be fulfilled by these 4 parameters in order to obtain a solution. Unfortunately it was not possible to solve the system and write explicit formulae for the solutions. Francis was nevertheless able to check that the two solutions per sequence found by Walter Trump's algorithm fulfilled the conditions. Thus by using this different method, Francis was able to confirm the validity of Walter's computer results. Francis Gaspalou has kindly authorised me to publish <a href="https://drive.google.com/file/d/0B7bucUs2xUSVa2ZlbnlPaVlQUXc/view?usp=sharing" rel="" target="_blank">his equations here:</a><br />
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<iframe height="718px" src="https://docs.google.com/viewer?srcid=0B7bucUs2xUSVa2ZlbnlPaVlQUXc&pid=explorer&efh=false&a=v&chrome=false&embedded=true" width="518px"></iframe><br />
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On the 13th January 2017 <a href="https://arxiv.org/abs/1110.6166" rel="" target="_blank">Bob Ziff</a> intervened, stating that if we agree that the system of equations is soluble, then it is soluble to any number of digits, and proved his point by calculating the slopes with 1000 digits, using the professional software Mathematica and the four equations of Francis Gaspalou.<br />
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Also, on the 13th January 2017, Walter Trump created a third-order linear area nearly-magic square with integer coordinates. This square is semi-magic with a magic constant of 940800! Walter points out that when you divide all the areas by 140, then the coordinates are no longer integers, but irrational numbers that can be exactly described using fractions and square roots. Walter has kindly authorised me to publish <a href="https://drive.google.com/file/d/0B7bucUs2xUSVMjdONlIxbWMxSm8/view?usp=sharing" rel="" target="_blank">his findings below:</a><br />
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<iframe height="718px" src="https://docs.google.com/viewer?srcid=0B7bucUs2xUSVMjdONlIxbWMxSm8&pid=explorer&efh=false&a=v&chrome=false&embedded=true" width="518px"></iframe><br />
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Francis Gaspalou has suggested that the next step might be to find a fourth-order area magic square with 6 continuous straight dissection lines, or even a concentric fifth-order area magic square. Why not imagine a contest, open to all, so as to find higher-order solutions of an equal mathematical importance to that of the third-order linear area magic squares?</div>
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If anyone wishes to contribute linear or other strict geometrical constructions of higher-order area magic squares, then please send me the x and y coordinates of the cell intersections that define the areas correctly up to two or more decimals after the commas. No prizes can be given, but the authors of pertinent solutions will, if they wish, have their solutions published here, and thus be able to bask in the reflected glory...<br />
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<u>Latest developments</u></h3>
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On the 19th January 2017 <a href="http://boingboing.net/2011/10/17/interview-with-futility-closet-blogger-greg-ross.html" rel="" target="_blank">Greg Ross</a> published an article on the subject of Area Magic Squares in his <a href="https://www.futilitycloset.com/2017/01/19/area-magic-squares/" rel="" target="_blank">Futility Closet</a> - An Idler's Miscellany of Compendious Amusements. This article has since been relayed by <a href="https://www.reddit.com/r/mathpics/comments/5p6o1l/magic_square_of_areas/" rel="" target="_blank">Reddit Mathpics</a>, <a href="http://simplementenumeros.blogspot.fr/2017/01/" rel="" target="_blank">Simplementenumeros</a>, <a href="http://www.primepuzzles.net/puzzles/puzz_865.htm" rel="" target="_blank">Prime Puzzles</a>, <a href="https://www.facebook.com/ThermallyStressedDairyCows/posts/594548574072628" rel="nofollow" target="_blank">Thermally Stressed Dairy Cows,</a> and by <a href="http://dailydesignstream.tumblr.com/post/156070975406/area-magic-squares/embed" rel="" target="_blank">Daily Design Stream,</a> amongst others.<br />
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On the 20th January 2017 I was aware that Walter Trump, (now joined by <a href="http://www.hbmeyer.de/magic.htm" rel="" target="_blank">Hans-Bernhard Meyer</a>), had already found that there are no cases of order-4 area magic squares with sequences of consecutive numbers. So I therefore began searching for non-consecutive number sequences that might also yield solutions in order-3, and produced the draft linear area magic square illustrated below:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmIdliRKVEA7_mTa0t8jH-pznGXqBdEeW1nibyq-g0fx4i-59Ak3HSFg5dNkr_LJdbBxujCv6p-FLnX9RPmkXslO7RpnrzVQDY9wRu5zYXWKTpQo5tD_MPI3QDD5eqgWgwSWRlqMe0tcM/s1600/WW_order_3_draft_linear_area_magic_square_seq_4-14_170120.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="Area Magic Square of Order-3 with sequences 4 to 6, 8 to 10, and 12 to 14." border="0" height="256" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmIdliRKVEA7_mTa0t8jH-pznGXqBdEeW1nibyq-g0fx4i-59Ak3HSFg5dNkr_LJdbBxujCv6p-FLnX9RPmkXslO7RpnrzVQDY9wRu5zYXWKTpQo5tD_MPI3QDD5eqgWgwSWRlqMe0tcM/s200/WW_order_3_draft_linear_area_magic_square_seq_4-14_170120.jpg" title="Area Magic Square of Order-3 with non-consecutive number sequence" width="228" /></a></div>
I sent this square to Walter Trump and the other members of the magic square circle asking if it could be verified using a computer program. Walter was quick to react, sending me precise coordinates for two solutions. Drawn-up using his coordinates, the two versions of this square are illustrated below:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgCT6j3oeKWu_Qp5n0ISsJSnQVX2oNo8AABvADehMPtxN_d3uXOWeqTiyMrqCVmAMdLA6RlZMpA0ILl0CnKXS04Hpnh0dUTC8XCwkOxj2B7-6KDGN2F8E1MKqcdd3GlpRC2Zhga32OygA/s1600/Puzzle+865-jvd2.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgCT6j3oeKWu_Qp5n0ISsJSnQVX2oNo8AABvADehMPtxN_d3uXOWeqTiyMrqCVmAMdLA6RlZMpA0ILl0CnKXS04Hpnh0dUTC8XCwkOxj2B7-6KDGN2F8E1MKqcdd3GlpRC2Zhga32OygA/s1600/Puzzle+865-jvd2.png" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh0ROJBrEZOMsDbWV1u9b6cMII-tTsDPK9IzIygeb0X9raJwTkHMseQKqNZJUIHUoIc4xPfDp6rYiu3u3cTSBSmQXcfpBt2ZMmKfJaksznrJBGQzmQWqexyggIBymIf8EhcP-qW9a8CORk/s1600/order_3_linear_area_magic_square_seq_4-14_v1.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="Order 3 linear area magic square verified" border="0" height="268" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh0ROJBrEZOMsDbWV1u9b6cMII-tTsDPK9IzIygeb0X9raJwTkHMseQKqNZJUIHUoIc4xPfDp6rYiu3u3cTSBSmQXcfpBt2ZMmKfJaksznrJBGQzmQWqexyggIBymIf8EhcP-qW9a8CORk/s200/order_3_linear_area_magic_square_seq_4-14_v1.jpg" title="" width="228" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_PMvtVaOQo6fgRCnVPwI2c8ecMv9CcE5DVvvIE84oEUcqj7T1hzJBkG0uZENza3BF_6Vnxdz1tyQFbqpvvXMPaFLXQSO4gpjH0ai5jPfL5Xx3gaSf2Js0voCdCwZAiPBqdR_7rqn-t18/s1600/order_3_linear_area_magic_square_seq_4-14_v2.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 3 linear area magic squre verified 2" border="0" height="268" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_PMvtVaOQo6fgRCnVPwI2c8ecMv9CcE5DVvvIE84oEUcqj7T1hzJBkG0uZENza3BF_6Vnxdz1tyQFbqpvvXMPaFLXQSO4gpjH0ai5jPfL5Xx3gaSf2Js0voCdCwZAiPBqdR_7rqn-t18/s200/order_3_linear_area_magic_square_seq_4-14_v2.jpg" title="" width="228" /></a></div>
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On the 3rd February 2017, responding to a <a href="http://www.primepuzzles.net/puzzles/puzz_865.htm" rel="" target="_blank">Prime Puzzle</a> challenge, Jan van Delden contributed the following palprime linear area magic square solution:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgCT6j3oeKWu_Qp5n0ISsJSnQVX2oNo8AABvADehMPtxN_d3uXOWeqTiyMrqCVmAMdLA6RlZMpA0ILl0CnKXS04Hpnh0dUTC8XCwkOxj2B7-6KDGN2F8E1MKqcdd3GlpRC2Zhga32OygA/s1600/Puzzle+865-jvd2.png" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgt4xK8fRb0QNTjUbsSlmLWiDwvuZnjooqESF5Gw7ckkQHttsTI9BRk1MeTgwEAB-XZy1YX_2760AplDhp-OC0B0x-oceI-awwPaT_qDuIFt9hqSPapHCrn4mCvi0Zo1dPKuqTaymX7PZc/s1600/Puzzle+865-jvd.png" style="margin-left: 1em; margin-right: 1em;"><img alt="Palindromic prime area magic square" border="0" height="231" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgt4xK8fRb0QNTjUbsSlmLWiDwvuZnjooqESF5Gw7ckkQHttsTI9BRk1MeTgwEAB-XZy1YX_2760AplDhp-OC0B0x-oceI-awwPaT_qDuIFt9hqSPapHCrn4mCvi0Zo1dPKuqTaymX7PZc/s320/Puzzle+865-jvd.png" title="" width="231" /></a></div>
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The palindromic primes used here are symmetrical numbers that remain the same when their digits are reversed. The magic sum of these 11-digit palindromic primes is 377,024,295,63. This area magic square is the conversion of a square that was originally sent by <a href="http://www.primepuzzles.net/images/cr&ja.gif" rel="" target="_blank">Carlos Rivera and Jaime Ayala</a> to <a href="http://magic-squares.net/primesqr.htm#Two%20palprime%20magic%20squares" rel="" target="_blank">Harvey Heinz</a> on the 22nd May 1999. Jan van Delden mentions that the direction coefficients of the lines are indicated in white, and that the quadrilaterals are numbered in the style of Francis Gaspalou. Full details of Jan van Delden's approach to the equations can be found in <a href="https://www.primepuzzles.net/puzzles/puzz_865.htm" rel="" target="_blank">Prime Puzzles</a>.</div>
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On the 4th February 2017 Jan van Delden contributed this second prime linear area magic square to Prime Puzzles:</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikGxJJMeSxny5sWMdM-J-U1-U1lqIGVzgzDp2gK6_aatRUBsofUCi9cICLUlCJjZVt0ADsiVlFzqn9hTDjIKo_9AXuch2W3pQVZmV5kjQkQcfBScvZQljHSzPsYbBLJobqkkyS5g2TeZ0/s1600/Puzzle+865-jvd2.png" style="margin-left: 1em; margin-right: 1em;"><img alt="order 3 prime number area magic square" border="0" height="231" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikGxJJMeSxny5sWMdM-J-U1-U1lqIGVzgzDp2gK6_aatRUBsofUCi9cICLUlCJjZVt0ADsiVlFzqn9hTDjIKo_9AXuch2W3pQVZmV5kjQkQcfBScvZQljHSzPsYbBLJobqkkyS5g2TeZ0/s320/Puzzle+865-jvd2.png" title="" width="231" /></a></div>
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Jan states that this prime area magic square has a minimal magic sum of S=213. Congratulations Jan, for these prime achievements!<br />
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Please note, that since the 5th March 2017, Jan has published a new paper entitled <a href="http://www.primepuzzles.net/puzzles/Pu865%20Area%20Magic%20Squares,%20JVD.pdf" target="_blank">"Area Magic Squares of Order 3,"</a> in which he extends his findings.<br />
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Seemingly, the number of order-3 linear area squares is infinite!<br />
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<h3>
<u>Related links</u></h3>
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A new post on <a href="https://carresmagiques.blogspot.com/2020/04/area-magic-squares-of-order-6.html" target="_blank">Area Magic Squares of Order-6</a> can be found in these pages since the 25th January 2017. </div>
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On the same day <a href="http://www.hbmeyer.de/index.html" rel="" target="_blank">Hans-Bernhard Meyer</a> published an article entitled <a href="http://www.hbmeyer.de/backtrack/area/index.html" target="_blank">Observations on 4x4 Area Magic Squares with vertical lines</a> in his website: Math'-pages.<br />
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Since the 3rd February 2017, <a href="http://www.trump.de/magic-squares/" rel="" target="_blank">Walter Trump</a> has published a chapter entitled <a href="http://www.trump.de/magic-squares/area-magic/index.html" target="_blank">Area Magic Squares</a> in his website: Notes on Magic Squares. This chapter includes many analyses and examples of area magic squares of the third and fourth-orders.<br />
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Since the 8th February 2017, <a href="https://carresmagiques.blogspot.com/2020/04/area-magic-squares-of-order-4.html" target="_blank">"Area Magic Squares of Order-4"</a> relates the first findings of area magic squares of the fourth-order.<br />
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Since the 11th February 2017, <a href="https://inderjtaneja.com/" rel="" target="_blank">Inder Jeet Taneja</a>, inspired by the research in area magic squares, has published a new paper entitled <a href="https://rgmia.org/papers/v20/v20a11.pdf" rel="" target="_blank">"Magic Squares with Perfect Square Number Sums."</a><br />
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Since the 5th March 2017, Jan van Delden has published a paper entitled <a href="http://www.primepuzzles.net/puzzles/Pu865%20Area%20Magic%20Squares,%20JVD.pdf" target="_blank">"Area Magic Squares of Order 3"</a> in which he presents an improved algorithm. His work also includes new findings in area <i>semi-magic</i> squares of order-3, and a shoelace formula to measure the deviation in area.<br />
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Since the 8th March 2017, following a tweet by <a href="https://twitter.com/Simon_Gregg/status/839584596266217484" rel="" target="_blank">Simon Gregg</a>, Microsiervos published an article entitled <a href="http://www.microsiervos.com/archivo/ciencia/cuadrados-areas-magicas.html" rel="" target="_blank">"Cuadrados de áreas mágicas."</a> This article has been relayed by <a href="http://www.inoreader.com/article/3a9c6e7f2171f5df-cuadrados-de-areas-magicas" rel="nofollow" target="_blank">Inoreader</a> amongst others.<br />
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Since the 22nd March 2017, writing for <a href="http://elpais.com/agr/el_aleph/a/" rel="" target="_blank">EL PAÍS</a>, <a href="https://elpais.com/autor/miguel_angel_morales_medina/a/" rel="" target="_blank">Miguel Ángel Morales</a> has included the subject of area magic squares in an article entitled <a href="http://elpais.com/elpais/2017/03/22/el_aleph/1490200756_349416.html" rel="" target="_blank">"No solo de números consecutivos vive el cuadrado mágico."</a><br />
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Since the 19th April 2017, writing for <a href="https://www.geogebra.org/" rel="" target="_blank">"Geogebra,"</a> Georg Wengler has included an article entitled <a href="https://www.geogebra.org/m/Htn8q8jY" rel="" target="_blank">"Magisches Flächen-Quadrat."</a><br />
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In the N° 487 2018 May issue of <a href="https://www.pourlascience.fr/sd/mathematiques/les-carres-magiques-daires-13295.php" rel="" target="_blank">"Pour La Science"</a> (the French edition of Scientific American), Professor Jean-Paul Delahaye has written an article entitled <a href="https://issuu.com/pourlascience/docs/pls_0487_pdf_apps/80" rel="" target="_blank">"Les Carrés Magiques d'Aires."</a><br />
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In the December 2018 issue of <a href="https://www.spektrum.de/magazin/spektrum-der-wissenschaft/" rel="" target="_blank">"Spektrum der Wissenschaft"</a> (a Springer Nature journal, and the German edition of Scientific American), Professor Jean-Paul Delahaye has written an article entitled <a href="https://www.spektrum.de/magazin/flaechenmagische-quadrate/1603760" rel="" target="_blank">"FLÄCHENMAGISCHE QUADRATE."</a><br />
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Since the 25th March 2019, Akehiko Takahashi, the webmaster of "Math Dojo," includes Area Magic Squares in his article entitled <a href="https://mathdojostl.wixsite.com/math-dojo/single-post/2019/03/25/Magic-Squares-and-Beyond#Area_Magic_Squares" rel="" target="_blank">"Magic Squares and Beyond."</a><br />
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On the 17th July 2019, a discussion in Japanese, about Area Magic Squares, began on the forum of <a href="https://twitter.com/wasanp_/status/1147903467383447552" rel="nofollow" target="_blank">"Japanese Traditional Mathematical Calculator."</a><br />
</div><div style="text-align: justify;"></div><div style="text-align: justify;"></div><div style="text-align: justify;"></div><div style="text-align: justify;"> </div><div style="text-align: justify;">Circa 2019, on the French recreational mathematics site <a href="http://www.diophante.fr/accueil" target="_blank">"Diophante,"</a> Michel Lafond published the first linear area magic square in a problem n° B138, entitled <a href="http://www.diophante.fr/problemes-par-themes/carres-et-figures-magiques/4447-b138-carre-magique-geometrique" target="_blank">"Carré magique géométrique,"</a> and asked mathematicians to prove its existence. Several solutions are proposed.<br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;">On the 1st January 2020, (exactly three years after the original area magic square greetings card!), an article about area magic patchwork entitled <a href="https://siebensachen-zum-selbermachen.blogspot.com/search?q=Fl%C3%A4chenmagische+Quadrate+-+aus+Stoff" rel="" target="_blank">"Flächenmagische Quadrate - aus Stoff,"</a> was published by the German blogger "Siebensachen-zum-Selbermachen."<br />
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On the 12th January 2020, the recreational mathematician <a href="https://en.wikipedia.org/wiki/Ed_Pegg_Jr." rel="" target="_blank">Ed Pegg Jr.</a>, published a "Magic Square with areas" on his site <a href="http://www.mathpuzzle.com/" rel="nofollow" target="_blank">"</a><a href="http://www.mathpuzzle.com/#Magic_Areas" rel="" target="_blank">Mathpuzzle."</a> </div><div style="text-align: justify;"> </div><div style="text-align: justify;">On the 20th May 2021, <a href="https://twitter.com/nosiika/status/1395488284151738368/photo/1" target="_blank">Morita Mizusumashi</a> (盛田みずすまし
@nosiika) tweeted a nice <a href="https://twitter.com/nosiika/status/1395488284151738368/photo/1" target="_blank">polyomino area magic square of order-3</a> constructed with 9 assemblies of <i>5</i> to <i>13 monominoes</i>. </div><div style="text-align: justify;"> </div><div style="text-align: justify;">
On the 21st May 2021, <a href="https://www.researchgate.net/profile/Yoshiaki-Araki" target="_blank">Yoshiaki Araki</a> (面積魔方陣がテセレーションみたいな件
@alytile) tweeted several order-4 and order-3 solutions in <a href="https://twitter.com/alytile/status/1395611974390542337/photo/1" target="_blank">a polyomino area magic square thread</a>. These included (amongst others) an order-4 example constructed with 16 assemblies of 5 to 20 dominoes.</div><div style="text-align: justify;"> </div><div style="text-align: justify;">On the 24th May 2021, Yoshiaki Araki then tweeted <a href="https://twitter.com/alytile/status/1396758907582779397/photo/1" target="_blank">an order-3 polyomino area magic square</a> constructed using assemblies of 1 to 9 same-shaped pentominoes! <a href="https://www.cs.purdue.edu/homes/gnf/book/Booknews/edoscub7.html" target="_blank">Edo Timmermans</a>, the author of this beautiful square, had apparently been inspired by Yoshiaki Araki's previous posts!</div><div style="text-align: justify;"><br /></div><div style="text-align: justify;">Since the 22nd June 2021, <a href="https://inderjtaneja.com/" target="_blank">Inder Taneja</a> has published a paper entitled <a href="https://zenodo.org/record/5009224" target="_blank">"Creative Magic Squares: Area Representations"</a> in which he explores polyomino area magic using perfect square magic sums.</div><div style="text-align: justify;"><br /></div><div style="text-align: justify;">A new post on <a href="https://carresmagiques.blogspot.com/2022/06/polyomino-area-magic-tori.html" target="_blank">"Polyomino Area Magic Tori"</a> can be found in these pages since the 7th June 2022. <br /></div>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com4tag:blogger.com,1999:blog-8742944687733483108.post-60844997607372569832016-11-30T11:52:00.003+01:002023-06-19T23:10:16.807+02:00Pandiagonality of the Squared Matrices of Associative and Related Magic Squares<div style="text-align: justify;">
The present study is inspired by <a href="http://www.region.com.ar/amela/franklinsquares/" rel="" target="_blank">Miguel Angel Amela's</a> paper dated September 2016, entitled "Powers of Associative Magic Squares," and by <a href="http://www.gaspalou.fr/magic-squares/index.htm" rel="" target="_blank">Francis Gaspalou's</a> paper dated 7th October 2016, entitled "Note on the features of the associative magic squares which give magic solutions when raised at an even power."<br />
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Both of these studies refer to an earlier paper by Charles K. Cook, Michael R. Bacon, and Rebecca A. Hillman; <a href="http://www.fq.math.ca/Papers1/48-4/Cook_Bacon_Hillman.pdf" rel="" target="_blank">“The Magicness of Powers of Some Magic Squares,”</a> published in The Fibonacci Quarterly, Volume 48, Number 4; 2010. </div>
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<h3>
Pandiagonality of the Squared Matrices of Associative and Related Magic Squares</h3>
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In the present study, which approaches the subject from a magic torus viewpoint, the use of formulae for generation enables an analysis of comparable magic tori throughout the different doubly-even and odd-orders. <i>Please note that there are no associative magic squares of singly-even-orders, as demonstrated by C. Planck in his <a href="http://www.jstor.org/stable/27900742" rel="" target="_blank">"Pandiagonal magics of orders 6 and 10 with minimal numbers,"</a> published in "The Monist," Volume 29, N° 2 (April 1919), pages 307-316.</i></div>
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The pages that follow show that both associative and non-associative matrices can yield magic solutions when squared. Although the study was initially intended for associative magic squares only, other types of magic squares, displayed on related magic tori, are now also included for the sake of comparison. <br />
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The research also reveals that recurring pandiagonal patterns appear on the squared matrices, throughout the higher-orders of magic tori generated by a same formula.<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi76YBCm5DhYGg9qcc7713kP5CL9kTOV0lyZWsyXsMrZQxPpWQAkS4QetHlwvhlZuLy9rbWg9yXZDHyeiQIs4m0JT3nyYrByyHTid9pxNd3I4PdJs2pYLS6TOV7o3O5T3LAA4h8z7vKSlo/s1600/Extract_pandiagonality_squared_matrices_associative_related_M_S_og.jpg" style="margin-left: auto; margin-right: auto;"><img alt="1/4 pandiagonal squared matrix of an associative magic square viewpoint of an order-12 semi-pandiagonal magic torus" border="0" data-original-height="840" data-original-width="1600" height="269" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi76YBCm5DhYGg9qcc7713kP5CL9kTOV0lyZWsyXsMrZQxPpWQAkS4QetHlwvhlZuLy9rbWg9yXZDHyeiQIs4m0JT3nyYrByyHTid9pxNd3I4PdJs2pYLS6TOV7o3O5T3LAA4h8z7vKSlo/s640/Extract_pandiagonality_squared_matrices_associative_related_M_S_og.jpg" title="" width="518" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: blue;"><span style="font-size: xx-small;">1/4 pandiagonal squared matrix of an associative magic square viewpoint of an order-12 semi-pandiagonal magic torus</span></span></td></tr>
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To view the paper <a href="https://drive.google.com/file/d/0B7bucUs2xUSVSWh4V3phZVBxQ1E/view?usp=sharing" rel="" target="_blank">"Pandiagonality of the Squared Matrices of Associative and Related Magic Squares,"</a> please note that if you click on the button that appears at the top right hand side of the pdf viewer below, a new window will open and full size pages will then be displayed, with options for zooming.</div>
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<iframe height="374px" src="https://docs.google.com/viewer?srcid=0B7bucUs2xUSVSWh4V3phZVBxQ1E&pid=explorer&efh=false&a=v&chrome=false&embedded=true" width="518px"></iframe>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-54187855186573385872016-10-25T10:51:00.004+02:002023-06-19T23:10:47.480+02:00A Perfect-Square-Order-9 Partially Pandiagonal Magic Square<div style="text-align: justify;">
A partially pandiagonal order-9 magic square has recently been brought to my attention by <a href="http://home.cc.umanitoba.ca/~loly/" rel="" target="_blank">Professor Peter D. Loly</a>, a Senior Scholar at the University of Manitoba.
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<div style="text-align: justify;">This order-9 square, initially published by the late Dame Kathleen Ollerenshaw in her article <a href="https://hobbydocbox.com/Chess/89464832-Constructing-pandiagonal-magic-squares-of-arbitrarily-large-size.html" target="_blank">"Constructing pandiagonal magic squares of arbitrarily large size"</a> (Mathematics Today, February 2006), was later analysed in 2013 by Ian Cameron, Adam Rogers and Peter D. Loly, in their paper <a href="http://pldml.icm.edu.pl/pldml/element/bwmeta1.element.bwnjournal-article-doi-10_7151_dmps_1147" rel="" target="_blank">"Signatura of Magic and Latin Integer Squares: Isentropic Clans and Indexing."</a></div><br />
<div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEizpYc6qoq2LXAByzp3h_8KOHjCPkjAW3Ij2aXnwsuL1Q3xyXyYqbeDrPw8ZUti7bUQJ2b8saL7qiTKrAUHtXAQXLmMAl7f_gvj06vFtXEb1-eZu4kBkJ9-eQPg_mYn-t9u8Fwjk7YSwuk/s1600/order-9_magic_square_dko9a.jpg" style="margin-left: auto; margin-right: auto;"><img alt="dko9a magic square first published by Dame Kathleen Ollerenshaw" border="0" data-original-height="836" data-original-width="1600" height="208" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEizpYc6qoq2LXAByzp3h_8KOHjCPkjAW3Ij2aXnwsuL1Q3xyXyYqbeDrPw8ZUti7bUQJ2b8saL7qiTKrAUHtXAQXLmMAl7f_gvj06vFtXEb1-eZu4kBkJ9-eQPg_mYn-t9u8Fwjk7YSwuk/s400/order-9_magic_square_dko9a.jpg" title="" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The Order-9 partially pandiagonal square dko9a, first published by Dame Kathleen Ollerenshaw</span></td></tr>
</tbody></table></div><br />
<div style="text-align: justify;">Cameron, Rogers and Loly have attributed the reference number dko9a to the square, and have described its characteristics in their table 4. In a recent correspondence, Peter D. Loly has pointed out that the square has a rank 5 matrix, which is the lowest he has seen for the order-9.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">The dko9a is a single square viewpoint of a partially pandiagonal torus, which in this case displays a total of 26 other essentially different partially pandiagonal squares, plus 54 essentially different semi-magic (although still partially pandiagonal) squares. It is practical to consider the dko9a square as a torus, in order to define its construction by a formula, and thus generate its torus ascendants and descendants throughout its respective lower and higher-orders. To find out more about the approach and the method, please refer to <a href="https://carresmagiques.blogspot.com/2020/04/magic-torus-coordinate-and-vector.html" target="_blank">"Magic Torus Coordinate and Vector Symmetries."</a></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">After observing the symmetries of the ninth-order partially pandiagonal square dko9a, we can deduce that if N is the order of the magic torus that displays this square, and if B represents any of the numbers of the torus from 1 to N², then <i>the modular coordinates of the position vectors from the number 1 to any of the numbers B can be expressed as follows:</i></div><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a data-flickr-embed="true" href="https://www.flickr.com/photos/williwalk/30459387922/in/dateposted-public/" style="margin-left: auto; margin-right: auto;" title="perfect_square_order-9_magic_torus_formula_desc_of_T4_173"><img alt="This is a modular arithmetic formula for a perfect square order-9 magic square or magic torus (magic torus descendant of T4173)." height="166" src="https://c3.staticflickr.com/6/5348/30459387922_ee42ce21c4.jpg" title="" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Formula for the position vectors of the numbers of the magic torus that displays the dko9a square</span></td></tr>
</tbody></table><br />
The second equation that follows is a simplified version in which B represents any of the numbers of the torus from<i> 0 to N²-1</i>, and the modular coordinates of the position vectors are specified from the origin number 0 to any of the numbers B. (Then, by adding 1 to all of the numbers <i>0 to N²-1</i> once they are positioned, we obtain the same result as in the first equation) :<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhb0pYO9NB4xZzT9xYoCf9m8H5n45jGqX_nsFuv4l1SQc89geXtOVoXNA7M8mrHdMRJZf_-pzcz775mkFNia8bctQ47kw8jx8Xc3d9jmnsiW6tPvXWwfXp8rkpVSLQsH5wbBusPLWG-GkQ/s1600/perfect_square_order_9_equation_2_CC_BY-NC-SA.jpg" style="margin-left: auto; margin-right: auto;"><img alt="This modular coordinate formula generates perfect square magic squares and magic tori." border="0" data-original-height="820" data-original-width="1600" height="164" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhb0pYO9NB4xZzT9xYoCf9m8H5n45jGqX_nsFuv4l1SQc89geXtOVoXNA7M8mrHdMRJZf_-pzcz775mkFNia8bctQ47kw8jx8Xc3d9jmnsiW6tPvXWwfXp8rkpVSLQsH5wbBusPLWG-GkQ/s320/perfect_square_order_9_equation_2_CC_BY-NC-SA.jpg" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Formula for the position vectors of the numbers <i>0 to N²-1</i> of the magic torus that displays the dko9a square <i>-1</i></span></td></tr>
</tbody></table><br />
<div style="text-align: justify;"><i>Generated by either of these methods,</i> the following figures show partially pandiagonal tori of direct lineage in the first, fourth, ninth, sixteenth and twenty-fifth perfect-square-orders:</div><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a data-flickr-embed="true" href="https://www.flickr.com/photos/williwalk/29921397363/in/album-72157672107537814/" style="margin-left: auto; margin-right: auto;" title="perfect_square_order-1_magic_torus_T1"><img alt="Perfect square order-1 magic torus T1" height="49" src="https://c4.staticflickr.com/6/5769/29921397363_3fc8e3f757_m.jpg" title="" width="54" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">First-order (1+1)/2 pandiagonal torus T1, ascendant of T4.173</span></td></tr>
</tbody></table><script async="" charset="utf-8" src="//embedr.flickr.com/assets/client-code.js"></script><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a data-flickr-embed="true" href="https://www.flickr.com/photos/williwalk/30518998126/in/album-72157672107537814/" style="margin-left: auto; margin-right: auto;" title="perfect_square_order-4_magic_torus_T4_173"><img alt="Perfect square order-4 magic torus T4.173" height="128" src="https://c7.staticflickr.com/6/5346/30518998126_8c802dcd22_m.jpg" title="" width="107" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Fourth-order (2+2)/8 pandiagonal (semi-pandiagonal) torus T4.173</span></td></tr>
</tbody></table><script async="" charset="utf-8" src="//embedr.flickr.com/assets/client-code.js"></script><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a data-flickr-embed="true" href="https://www.flickr.com/photos/williwalk/29922779403/in/album-72157672107537814/" style="margin-left: auto; margin-right: auto;" title="perfect_square_order-9_magic_torus_desc_of_T4_173"><img alt="Perfect square order-9 magic torus descendant of magic torus T4.173" height="193" src="https://c4.staticflickr.com/6/5728/29922779403_09692b898e.jpg" title="" width="214" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;"> Ninth-order (3+9)/18 pandiagonal torus, descendant of T4.173</span><br />
<span style="font-size: xx-small;">(seen from Ollerenshaw's dko9a magic square viewpoint) </span></td></tr>
</tbody></table><script async="" charset="utf-8" src="//embedr.flickr.com/assets/client-code.js"></script><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a data-flickr-embed="true" href="https://www.flickr.com/photos/williwalk/30554941625/in/album-72157672107537814/" style="margin-left: auto; margin-right: auto;" title="perfect_square_order-16_magic_torus_desc_of_T4_173"><img alt="Perfect square order-16 magic torus descendant of magic torus T4.173" height="324" src="https://c2.staticflickr.com/6/5494/30554941625_ea94528df1.jpg" title="" width="357" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Sixteenth-order (4+8)/32 pandiagonal torus, descendant of T4.173</span></td></tr>
</tbody></table><script async="" charset="utf-8" src="//embedr.flickr.com/assets/client-code.js"></script><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a data-flickr-embed="true" href="https://www.flickr.com/photos/williwalk/29921384913/in/album-72157672107537814/" style="margin-left: auto; margin-right: auto;" title="perfect_square_order-25_magic_torus_desc_of_T4_173"><img alt="Perfect square order-25 magic torus descendant of T4.173" height="474" src="https://c2.staticflickr.com/6/5802/29921384913_4fa5d3b354_z.jpg" title="" width="518" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Twenty-fifth-order (5+25)/50 pandiagonal torus, descendant of T4.173</span></td></tr>
</tbody></table><script async="" charset="utf-8" src="//embedr.flickr.com/assets/client-code.js"></script><br />
<div style="text-align: justify;">Apart from the first-order torus T1, the immediate torus ascendant of the dko9a is the fourth-order semi-pandiagonal torus with <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">index number T4.173</a> and <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">type number T4.02.2.11</a>. This torus displays eight semi-pandiagonal squares with Frénicle index numbers 89, 183, 323, 368, 464, 539, 661, and 698. The T4.173 torus also displays eight semi-magic squares and is entirely covered by 8 sub-magic 2x2 squares. For details of the classification of the 255 fourth-order magic tori by type numbers, please refer to <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">"255 Fourth-Order Magic Tori, and 1 Third-Order Magic Torus."</a> For details of the classification of the 255 fourth-order magic tori by index numbers, (which, by using normalised squares is in a way a homage to Bernard Frénicle de Bessy), please refer to the <a href="https://drive.google.com/file/d/1z9qcsDbGbVltWCm19_k_jqgKnisddhHp/view" target="_blank">"Table of Fourth-Order Magic Tori."</a></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Please note that other formulae may well generate different torus ascendants or descendants. However, the formulae shown above are <i>ideal</i>, as they theoretically generate an infinite number of similarly constructed partially pandiagonal torus descendants throughout the higher-perfect-square-orders.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Observing the partially pandiagonal characteristics of these perfect-square-order magic tori suggests that there are recurring patterns:<br />
In the odd-orders, the patterns of the magic diagonals are (1+1)/2 for the first-order, (3+9)/18 for the ninth-order, and (5+25)/50 for the twenty-fifth-order. This suggests a possible recurring pattern of (√<span style="text-decoration: overline;">N</span>+N)/2N for the magic diagonals of the odd-orders that are generated by the perfect-square-order formulae described above.<br />
In the even-orders, the patterns of the magic diagonals are (2+2)/2 for the fourth-order, and (4+8)/32 for the sixteenth-order. This suggests a possible recurring pattern of (√<span style="text-decoration: overline;">N</span>+N/2)/2N for the magic diagonals of the even-orders that are generated by the perfect-square-order formulae described above.<br />
Testing in higher-orders, or a mathematical proof, will validate or invalidate these hypotheses.</div>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-41480774101532302492016-09-10T10:29:00.004+02:002023-06-19T23:11:37.677+02:00Magic Torus Coordinate and Vector Symmetries<p style="text-align: justify;">
Magic squares have fascinated mathematicians for centuries and they continue to do so today. However, many questions remain unanswered, and this study proposes a different perspective in order to shed new light on what magic squares are and how they work. Considering magic squares to be flattened partial viewpoints of convex or concave magic tori, the implied Gaussian surfaces require a modular arithmetic approach that is tested and analysed here.</p>
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Until today, most magic square construction methods use base squares, whilst <i>"Magic Torus Coordinate and Vector Symmetries"</i> proposes modular coordinate equations that not only define specific magic tori, but also generate their magic torus descendants. </p>
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The construction of Agrippa's traditional magic squares is analysed in detail for each of the seven planetary magic tori, and modular coordinate equations are defined that generate descendant tori throughout the respective higher-orders, whether they be odd, doubly-even, or singly-even.</p>
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The unique third-order magic torus and also a fifth-order pandiagonal torus of Latin construction are examined in detail. The modular coordinate equations that are defined generate an interesting variety of higher-odd-order descendant tori. </p>
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The study also explores the construction of the 12 different types of fourth-order magic tori, as well as the generation of their doubly-even magic torus descendants. In addition, a fourth-order Candy-style perfect square pandiagonal torus, and a fourth-order unidirectionally pandiagonal semi-magic torus, are each analysed in detail, and their torus descendants generated, throughout their respective higher-orders.</p>
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At the end of the study observations are made, and some conclusions are drawn as to the signification of the findings, and the potential for future research.</p>
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Some sample illustrations of a fourth-order partially pandiagonal torus and its partially pandiagonal torus descendants are shown below:</p>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFplSwfMMi71y7Cz-J66jzqFoVApYK53yLwKYxOnXHnrNB4l22yb0aNaad5TWfmFGCAbPasahN535HsAT_nCUKjZyKrkVxc0NUdrasmpRGqucTtdffq6XVNp9IF7IYecYvONOyUEVFSmw/s1600/T4_195_magic_torus.jpg" style="margin-left: auto; margin-right: auto;"><img alt="T4.195 partially pandiagonal magic torus of order-4" border="0" data-original-height="694" data-original-width="1326" height="104" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFplSwfMMi71y7Cz-J66jzqFoVApYK53yLwKYxOnXHnrNB4l22yb0aNaad5TWfmFGCAbPasahN535HsAT_nCUKjZyKrkVxc0NUdrasmpRGqucTtdffq6XVNp9IF7IYecYvONOyUEVFSmw/s200/T4_195_magic_torus.jpg" title="" width="200" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">T4.195 4th-order partially pandiagonal torus</span></td></tr></tbody></table>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a data-flickr-embed="true" href="https://www.flickr.com/photos/williwalk/29588711345/in/dateposted-public/" style="margin-left: auto; margin-right: auto;" title="T4_195_magic_torus_order_8_descendant"><img alt="T4.195 partially pandiagonal magic torus descendant of order-8" height="200" src="https://c2.staticflickr.com/9/8172/29588711345_1995e182bb_n.jpg" title="" width="200" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">8th-order partially pandiagonal torus, direct descendant of T4.195</span></td></tr></tbody></table>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a data-flickr-embed="true" href="https://www.flickr.com/photos/williwalk/29478873902/in/album-72157673589124526/" style="margin-left: auto; margin-right: auto;" title="T4_195_magic_torus_order_12_descendant"><img alt="T4.195 partially pandiagonal magic torus descendant of order-12" height="275" src="https://farm9.staticflickr.com/8245/29478873902_f78f430434_b.jpg" title="" width="300" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">12th-order partially pandiagonal torus, direct descendant of T4.195</span></td></tr></tbody></table>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a data-flickr-embed="true" href="https://www.flickr.com/photos/williwalk/29478873132/in/dateposted-public/" style="margin-left: auto; margin-right: auto;" title="T4_195_magic_torus_order_16_descendant"><img alt="T4.195 partially pandiagonal magic torus descendant of order-16" height="400" src="https://c5.staticflickr.com/9/8077/29478873132_a393db0c06.jpg" title="" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">16th-order partially pandiagonal torus, direct descendant of T4.195</span></td></tr></tbody></table>
<script async="" charset="utf-8" src="//embedr.flickr.com/assets/client-code.js"></script>
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<p style="text-align: justify;">
To download <i>"Magic Torus Coordinate and Vector Symmetries"</i> from Google Drive, please use the following link: <a href="https://drive.google.com/uc?export=download&confirm=xu1G&id=0B7bucUs2xUSVZUdWaUFSXzVfdjQ" target="_blank">MTCVS 161019</a>. The 134 Mo pdf file exceeds the maximum size (25 Mo) that Google Drive can scan, but as <u>the file is virus free</u> you can download it safely. Depending on the speed of your computer, the download can take up to two or three minutes to complete.</p>
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<div class="separator" style="clear: both; text-align: center;">
<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-59457854742904981822016-08-29T20:28:00.002+02:002023-06-19T23:12:18.049+02:00Complementary Number Patterns on Fourth-Order Magic Tori<div style="text-align: justify;">
The 880 fourth-order magic squares were first identified and listed by Bernard Frénicle de Bessy in his « Table générale des quarrez magiques de quatre, » which was published posthumously in 1693, in his book « Des quarrez magiques. » The census of these 880 4x4 squares is given in the appendix to the book « New Recreations With Magic Squares » by William H. Benson and Oswald Jacoby (Edition 1976), and also on the website of the late Harvey D. Heinz: <a href="http://www.magic-squares.net/order4lista.htm" target="_blank">Frénicle n° 1 <span id="goog_605753066"></span><span id="goog_605753067"></span>à 200</a>, <a href="http://www.magic-squares.net/order4listb.htm" target="_blank">Frénicle n° 201 à 400</a>, <a href="http://www.magic-squares.net/order4listc.htm" target="_blank">Frénicle n° 401 à 600</a>, <a href="http://www.magic-squares.net/order4listd.htm" target="_blank">Frénicle n° 601 à 880</a>.</div>
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Further to Bernard Frénicle de Bessy's initial findings, Henry Ernest Dudeney then classified the 880 fourth-order magic squares under 12 pattern types, in "The Queen" in 1910, (later republished in his book <a href="https://archive.org/stream/AmusementsInMathematicspdf/AmusementsInMathematics#page/n175/mode/2up/search/Magic+square+problems" rel="" target="_blank">"Amusements in Mathematics"</a> in 1917). These patterns were determined through the observation of the relative positions of complementary pairs of numbers (which add up to N²+1 when N is the order of the square).</div>
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Although the different Dudeney pattern types can indeed be observed on fourth-order magic squares, they cannot be used for the classification of the fourth-order magic tori that display these squares. A Dudeney pattern type can be misleading because it depends on a bordered magic square viewpoint, whilst the magic torus that displays the magic square has a limitless surface...</div>
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In the study that follows the complementary number patterns are therefore tested, by comparing a developed torus surface and two traditional Frénicle magic square viewpoints for each of the 12 different types of fourth-order magic tori.</div>
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<h2 style="text-align: justify;">
<u>Complementary number patterns of each fourth-order magic torus type</u></h2>
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<h3 style="text-align: justify;">
<u>General information on the magic torus index and type numbers</u> </h3>
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In addition to the Frénicle index numbers and the Dudeney types that have already been mentioned above, the present study also uses the index and type numbers of the fourth-order magic tori. For readers who may not be acquainted with the subject, essential information can be found in the following pages:</div>
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In a previous article <a href="https://carresmagiques.blogspot.com/2020/04/255-fourth-order-magic-tori-and-1-third.html" target="_blank">"255 Fourth-Order Magic Tori, and 1 Third-Order Magic Torus,"</a> the fourth-order magic tori have been classed in 12 types, and each magic torus has received a specific type number.</div>
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In a previous article <a href="https://carresmagiques.blogspot.com/2020/04/table-of-fourth-order-magic-tori.html" target="_blank">"Table of Fourth-Order Magic Tori,"</a> so as to facilitate the identification of a magic torus beginning with any magic square, a standard torus form has also been defined, and each of the 255 fourth-order magic tori has received a specific index number.</div>
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<h3 style="text-align: justify;">
<u>Complementary number patterns of the pandiagonal tori type T4.01</u> </h3>
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The 3 pandiagonal tori type T4.01 are here represented by the pandiagonal torus with index n° T4.01.1 (torus type n° T4.01.1). This pandiagonal torus displays 16 pandiagonal squares with Frénicle index n°s 102, 104, 174, 201, 279, 281, 365, 393, 473, 530, 565, 623, 690, 748, 785 and 828. All of these squares, (including the Frénicle index n°s 102 and 174 illustrated here), show complementary number patterns that are Dudeney type I.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUPL1EJuxMTfiGegBilVWlzT68Kwhua5fiUSW1QbkvDnLSorKOxbTNXZAUGh4n9qsN2_Wu4_Seq67Id9ijdxNoyuXadd6SEDfTZCmf7F9HU7B4WBFpNBxs7nMdVPZeKHvyfba0AveGBRA/s1600/T401_MT_og.png" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 pandiagonal magic torus complementary number patterns" border="0" data-original-height="840" data-original-width="1600" height="155" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUPL1EJuxMTfiGegBilVWlzT68Kwhua5fiUSW1QbkvDnLSorKOxbTNXZAUGh4n9qsN2_Wu4_Seq67Id9ijdxNoyuXadd6SEDfTZCmf7F9HU7B4WBFpNBxs7nMdVPZeKHvyfba0AveGBRA/s320/T401_MT_og.png" title="" width="300" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXIpWneqE0dCRKyXxcHV8ZbGT3LXnZZKoM4-0hrk_imSGA5OA69c5H59y7J52gWDx0E3WmvvY9GsamT1vrjb0JAQvotzOSivEPkUT9MuGJXOtJnDp97h1IBS5WRUolueTQqQ2RiMKycW4/s1600/T401_MS.png" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 pandiagonal magic square complementary number patterns" border="0" data-original-height="662" data-original-width="1600" height="132" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXIpWneqE0dCRKyXxcHV8ZbGT3LXnZZKoM4-0hrk_imSGA5OA69c5H59y7J52gWDx0E3WmvvY9GsamT1vrjb0JAQvotzOSivEPkUT9MuGJXOtJnDp97h1IBS5WRUolueTQqQ2RiMKycW4/s320/T401_MS.png" title="" width="320" /></a></div>
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<h3 style="text-align: justify;">
<u>Complementary number patterns of the semi-pandiagonal tori type T4.02.1 </u></h3>
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The 24 semi-pandiagonal tori type T4.02.1 are here represented by the semi-pandiagonal torus with index n° T4.115 (torus type n° T4.02.1.09). This semi-pandiagonal torus displays 8 semi-pandiagonal squares with Frénicle index n°s 48, 192, 255, 400, 570, 734, 763 and 824. Half of these squares, (including the Frénicle index n° 192 illustrated here), show complementary number patterns that are Dudeney type IV. The other half, (including the Frénicle index n° 48 illustrated here), show complementary number patterns that are Dudeney type VI.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEil64nSzMu-oHeoWiwhVrH8Zxt4MYCQ0rIYZoAEy_9HmeHS0eSimCfbQp66vC7c6Vg1aNxBl-m1zLMr_tIH8X4BHcunwfmzZCgJ0ztjzqDiKBzC6vJggKuz0p7qBGNbdb8GKCvsUizINqM/s1600/Compl_numbers_torus_T4_02_1.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 semi-pandiagonal magic Square complementary number patterns Dudeney types IV and VI" border="0" height="139" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEil64nSzMu-oHeoWiwhVrH8Zxt4MYCQ0rIYZoAEy_9HmeHS0eSimCfbQp66vC7c6Vg1aNxBl-m1zLMr_tIH8X4BHcunwfmzZCgJ0ztjzqDiKBzC6vJggKuz0p7qBGNbdb8GKCvsUizINqM/s640/Compl_numbers_torus_T4_02_1.jpg" title="" width="525" /></a></div>
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<h3 style="text-align: justify;">
<u>Complementary number patterns of the semi-pandiagonal tori type T4.02.2</u></h3>
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The 12 semi-pandiagonal tori type T4.02.2 are here represented by the semi-pandiagonal torus with index n° T4.059 (torus type n° T4.02.2.01). This semi-pandiagonal torus displays 8 semi-pandiagonal squares with Frénicle index n°s 21, 176, 213, 361, 445, 591, 808 and 860. Half of these squares, (including the Frénicle index n° 21 illustrated here), show complementary number patterns that are Dudeney type II. The other half, (including the Frénicle index n° 176 illustrated here), show complementary number patterns that are Dudeney type III.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjF3SNoNJFdJdnv-P9NsEpGnJcFsMT3EmURYoxd3gd-SsgPoWcicaK062pGydrlj8vceueR-KMbLlksIv30pECz3Z05VTEtXjXpA9_fm0GAh8UXbfNk5NxzNIUUTninu0v-yF8Ar4mhgrI/s1600/Compl_numbers_torus_T4_02_2.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 semi-pandiagonal magic square complementary number patterns Dudeney types II and III" border="0" height="138" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjF3SNoNJFdJdnv-P9NsEpGnJcFsMT3EmURYoxd3gd-SsgPoWcicaK062pGydrlj8vceueR-KMbLlksIv30pECz3Z05VTEtXjXpA9_fm0GAh8UXbfNk5NxzNIUUTninu0v-yF8Ar4mhgrI/s640/Compl_numbers_torus_T4_02_2.jpg" title="" width="525" /></a></div>
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<h3 style="text-align: justify;">
<u>Complementary number patterns of the semi-pandiagonal tori type T4.02.3</u></h3>
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The 12 semi-pandiagonal tori type T4.02.3 are here represented by the semi-pandiagonal torus with index n° T4.085 (torus type n° T4.02.3.01). This semi-pandiagonal torus displays 8 semi-pandiagonal squares with Frénicle index n°s 32, 173, 228, 362, 425, 577, 798 and 853. All of these squares, (including the Frénicle index n°s 173 and 228 illustrated here), show complementary number patterns that are Dudeney type V. </div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEivZ5VzTRGYa2kER7UoCS2IDrK1wvElDIg2BVlfdp8EYQJGR-fuVcwGXkZadizxQPz-TeiPxc9u9FJSOZ4_3doeM9e4TbDto-B1WmacXV96sLp4XpPBwd9DPHmpBKKC0U2zIVFiryFULZ0/s1600/Compl_numbers_torus_T4_02_3.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 semi-pandiagonal magic square complementary number patterns Dudeney type V" border="0" height="136" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEivZ5VzTRGYa2kER7UoCS2IDrK1wvElDIg2BVlfdp8EYQJGR-fuVcwGXkZadizxQPz-TeiPxc9u9FJSOZ4_3doeM9e4TbDto-B1WmacXV96sLp4XpPBwd9DPHmpBKKC0U2zIVFiryFULZ0/s640/Compl_numbers_torus_T4_02_3.jpg" title="" width="525" /></a></div>
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<h3 style="text-align: justify;">
<u>Complementary number patterns of the partially pandiagonal tori type T4.03.1</u></h3>
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The 6 partially pandiagonal tori type T4.03.1 are here represented by the partially pandiagonal torus with index n° T4.108 (torus type n° T4.03.1.1). This partially pandiagonal torus displays 4 partially pandiagonal squares with Frénicle index n°s 46, 50, 337 and 545. All of these squares, (including the Frénicle index n°s 46 and 545 illustrated here), show complementary number patterns that are Dudeney type VI.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiLT6GjSyJbcwuIghtGG07tlhzklO23o9ZPaRZ-vYuX36OCeRHxnRM-BbzVkKRCpMi_T-PUpjzZpAzc0g_ZuLjV2wSWyOU0a4l3WFE27bX1diESywspp8MM_Dvezk1RHKH1i2VVJ9otymU/s1600/Compl_numbers_torus_T4_03_1.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 partially pandiagonal magic square complementary number patterns Dudeney type VI" border="0" height="138" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiLT6GjSyJbcwuIghtGG07tlhzklO23o9ZPaRZ-vYuX36OCeRHxnRM-BbzVkKRCpMi_T-PUpjzZpAzc0g_ZuLjV2wSWyOU0a4l3WFE27bX1diESywspp8MM_Dvezk1RHKH1i2VVJ9otymU/s640/Compl_numbers_torus_T4_03_1.jpg" title="" width="525" /></a></div>
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<div style="text-align: justify;">
<br />
As already mentioned in <a href="https://carresmagiques.blogspot.com/2020/04/a-new-census-of-fourth-order-magic.html" target="_blank">"A New Census of Fourth-Order Magic Squares,"</a> Dudeney overlooked the partially pandiagonal characteristics, and mistakenly classified these squares as "simple." </div>
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<h3 style="text-align: justify;">
<u>Complementary number patterns of the partially pandiagonal tori type T4.03.2</u></h3>
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<div style="text-align: justify;">
The 12 partially pandiagonal tori type T4.03.2 are here represented by the partially pandiagonal torus with index n° T4.195 (torus type n° T4.03.2.06). This partially pandiagonal torus displays 4 partially pandiagonal squares with Frénicle index n°s 208, 525, 526 and 693. Half of these squares, (including the Frénicle index n° 693 illustrated here), show complementary number patterns that are Dudeney type VII. The other half, (including the Frénicle index n° 208 illustrated here), show complementary number patterns that are Dudeney type IX.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJdrGBT2T9uteWZwH_KCKxITYaVh8FiQkBpJvrxkFAIhC5RMHPu_1DTaCJXOwJRPjARhwtzU_tTg80i1djWdXZo666PdgFfwxhkNdLqBoaY_PyUEiP-RrFHcCPwJF1Vy3yyrTxvZaU9JM/s1600/Compl_numbers_torus_T4_03_2.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 partially pandiagonal magic square complementary number patterns Dudeney types VII and IX" border="0" height="138" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJdrGBT2T9uteWZwH_KCKxITYaVh8FiQkBpJvrxkFAIhC5RMHPu_1DTaCJXOwJRPjARhwtzU_tTg80i1djWdXZo666PdgFfwxhkNdLqBoaY_PyUEiP-RrFHcCPwJF1Vy3yyrTxvZaU9JM/s640/Compl_numbers_torus_T4_03_2.jpg" title="" width="525" /></a></div>
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<br /></div>
<div style="text-align: justify;">
As already mentioned in <a href="https://carresmagiques.blogspot.com/2020/04/a-new-census-of-fourth-order-magic.html" target="_blank">"A New Census of Fourth-Order Magic Squares,"</a> Dudeney overlooked the partially pandiagonal characteristics, and mistakenly classified these squares as "simple." </div>
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<h3 style="text-align: justify;">
<u>Complementary number patterns of the partially pandiagonal tori type T4.03.3</u></h3>
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<div style="text-align: justify;">
The 2 partially pandiagonal tori type T4.03.3 are here represented by the partially pandiagonal torus with index n° T4.217 (torus type n° T4.03.3.1). This partially pandiagonal torus displays 4 partially pandiagonal squares with Frénicle index n°s 181, 374, 484 and 643. All of these squares, (including the Frénicle index n°s 484 and 643 illustrated here), show complementary number patterns that are Dudeney type XI.</div>
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<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiNiCVeBCKjzYOPkXtC29QywDiQlVzD45yfY6XpkV0JIBHSXLn3_GH_DeSW6ZaHIQ1J8ig4dYmRwHBn17kUstL1Kq0lPu8I7ijj437NYRKhH4oqGzj10uHsDFycRD4dctsLDGDNTJ4eToA/s1600/Compl_numbers_torus_T4_03_3.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 partially pandiagonal magic square complementary number patterns Dudeney type XI" border="0" height="138" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiNiCVeBCKjzYOPkXtC29QywDiQlVzD45yfY6XpkV0JIBHSXLn3_GH_DeSW6ZaHIQ1J8ig4dYmRwHBn17kUstL1Kq0lPu8I7ijj437NYRKhH4oqGzj10uHsDFycRD4dctsLDGDNTJ4eToA/s640/Compl_numbers_torus_T4_03_3.jpg" title="" width="525" /></a></div>
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<div style="text-align: justify;">
As already mentioned in <a href="https://carresmagiques.blogspot.com/2020/04/a-new-census-of-fourth-order-magic.html" target="_blank">"A New Census of Fourth-Order Magic Squares,"</a> Dudeney overlooked the partially pandiagonal characteristics, and mistakenly classified these squares as "simple."</div>
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<h3 style="text-align: justify;">
<u>Complementary number patterns of the partially pandiagonal tori type T4.04</u></h3>
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<div style="text-align: justify;">
The 4 partially pandiagonal tori type T4.04 are here represented by the partially pandiagonal torus with index n° T4.096 (torus type n° T4.04.1). This partially pandiagonal torus displays 2 partially pandiagonal squares with Frénicle index n°s 40 and 522. The square with Frénicle index n° 40 (illustrated here) shows a complementary number pattern that is Dudeney type VIII, whilst the other square with Frénicle index n° 522 (illustrated here) shows a complementary number pattern that is Dudeney type X.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEHXBbAT-L-U51gWokJ7sHBiZMh6rKhQXG9k4rTkwuRAXqDy63C6Bn1ASo8nG8-Rloan9CDGr3Pc6SJ6sLbbT-_jZWJJeL2nCrNiFEEg6DmosK-ZFhBqF7J1qW6-JhymVq-VsTNryNa5c/s1600/Compl_numbers_torus_T4_04.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 partially pandiagonal magic square complementary number patterns Dudeney types VIII and X" border="0" height="138" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEHXBbAT-L-U51gWokJ7sHBiZMh6rKhQXG9k4rTkwuRAXqDy63C6Bn1ASo8nG8-Rloan9CDGr3Pc6SJ6sLbbT-_jZWJJeL2nCrNiFEEg6DmosK-ZFhBqF7J1qW6-JhymVq-VsTNryNa5c/s640/Compl_numbers_torus_T4_04.jpg" title="" width="525" /></a></div>
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As already mentioned in <a href="https://carresmagiques.blogspot.com/2020/04/a-new-census-of-fourth-order-magic.html" target="_blank">"A New Census of Fourth-Order Magic Squares,"</a> Dudeney overlooked the partially pandiagonal characteristics, and mistakenly classified these squares as "simple."</div>
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<h3 style="text-align: justify;">
<u>Complementary number patterns of the basic magic tori type T4.05.1</u> </h3>
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<div style="text-align: justify;">
The 92 basic magic tori type T4.05.1 are here represented by the basic magic torus with index n° T4.002 (torus type n° T4.05.1.01). This basic magic torus displays 2 basic magic squares with Frénicle index n°s 1 and 458. Both of these squares, illustrated here, show complementary number patterns that are Dudeney type VI.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjREcmJtLPXzikmyjZ8n4sZ-MwVZPJElSEnuxoVmquGdyMi8ZALpeemvIJroGIz77rldZk5ba52087ZZaed0NTQp3GRZIDNp8AbArMIDtiEIgbDFd7-g844bzE1cXZ88ffgHhsfv4NDXB4/s1600/Compl_numbers_torus_T4_05_1.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 basic magic square complementary number patterns Dudeney types VI" border="0" height="136" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjREcmJtLPXzikmyjZ8n4sZ-MwVZPJElSEnuxoVmquGdyMi8ZALpeemvIJroGIz77rldZk5ba52087ZZaed0NTQp3GRZIDNp8AbArMIDtiEIgbDFd7-g844bzE1cXZ88ffgHhsfv4NDXB4/s640/Compl_numbers_torus_T4_05_1.jpg" title="" width="525" /></a></div>
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<h3 style="text-align: justify;">
<u>Complementary number patterns of the basic magic tori type T4.05.2</u> </h3>
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<div style="text-align: justify;">
The 32 basic magic tori type T4.05.2 are here represented by the basic magic torus with index n° T4.049 (torus type n° T4.05.2.01). This basic magic torus displays 2 basic magic squares with Frénicle index n°s 23 and 767. The square with Frénicle index n° 767 (illustrated here) shows a complementary number pattern that is Dudeney type VII, whilst the square with Frénicle index n° 23 (illustrated here) shows a complementary number pattern that is Dudeney type IX.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCN_hg1de8x_lLOzgoE3L0Qe_OdpmH61F2kgbgXKo3s45bpu8siGdqmgpc6C62oC5KZzheeEWzlHHzwAY-NZcBbFjwV_Hc2t7M93e7wk2U_IDn2gXQxlxEHR7uGKjkTfSzNhTIuNDCC90/s1600/Compl_numbers_torus_T4_05_2.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 basic magic square complementary number patterns Dudeney types VII and IX" border="0" height="138" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCN_hg1de8x_lLOzgoE3L0Qe_OdpmH61F2kgbgXKo3s45bpu8siGdqmgpc6C62oC5KZzheeEWzlHHzwAY-NZcBbFjwV_Hc2t7M93e7wk2U_IDn2gXQxlxEHR7uGKjkTfSzNhTIuNDCC90/s640/Compl_numbers_torus_T4_05_2.jpg" title="" width="525" /></a></div>
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</div>
<h3 style="text-align: justify;">
<u>Complementary number patterns of the basic magic tori type T4.05.3</u></h3>
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<div style="text-align: justify;">
The 4 basic magic tori type T4.05.3 are here represented by the basic magic torus with index n° T4.005 (torus type n° T4.05.3.1). This basic magic torus displays 2 basic magic squares with Frénicle index n°s 3 and 613. Both of these squares, illustrated here, show complementary number patterns that are Dudeney type XII.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-Gw2q9lF4AeuClyisxfFA7hCtA0Pw_iDKrZp7U1uwkT7CDSmkcHuArw_ubSJuwm1F1MHATEblfNkgwBzJu2NxBqGPbJWm2Fn1Zazmy48CdqWFN2Gty69IPlQXgB7O2FTdvLA05olNCY4/s1600/Compl_numbers_torus_T4_05_3.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 basic magic square complementary number patterns Dudeney type XII" border="0" height="136" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-Gw2q9lF4AeuClyisxfFA7hCtA0Pw_iDKrZp7U1uwkT7CDSmkcHuArw_ubSJuwm1F1MHATEblfNkgwBzJu2NxBqGPbJWm2Fn1Zazmy48CdqWFN2Gty69IPlQXgB7O2FTdvLA05olNCY4/s640/Compl_numbers_torus_T4_05_3.jpg" title="" width="525" /></a></div>
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<h3 style="text-align: justify;">
<u>Complementary number patterns of the basic magic tori type T4.05.4</u></h3>
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<div style="text-align: justify;">
The 52 basic magic tori type T4.05.4 are here represented by the basic magic torus with index n° T4.019 (torus type n° T4.05.4.1). This basic magic torus displays 2 basic magic squares with Frénicle index n°s 8 and 343. The square with Frénicle index n° 8 (illustrated here) shows a complementary number pattern that is Dudeney type VIII, whilst the square with Frénicle index n° 343 (illustrated here) shows a complementary number pattern that is Dudeney type X.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjn7ZjYOICoRKBlP03HaLPnj3hHMUNMWZqN4DRj30YapqC4rrhnMyDcd_xACEo3y61tO9in4JjXydyh_zOVfFZharKRQhHoZMwxc74ZuP-6s82qT3CUACEeuIGALGMdcwE0ir3SOppGSdU/s1600/Compl_numbers_torus_T4_05_4.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="order 4 basic magic square complementary number patterns Dudeney types VIII and X" border="0" height="138" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjn7ZjYOICoRKBlP03HaLPnj3hHMUNMWZqN4DRj30YapqC4rrhnMyDcd_xACEo3y61tO9in4JjXydyh_zOVfFZharKRQhHoZMwxc74ZuP-6s82qT3CUACEeuIGALGMdcwE0ir3SOppGSdU/s640/Compl_numbers_torus_T4_05_4.jpg" title="" width="525" /></a></div>
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<u>Conclusions</u> </h2>
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We can see that the Dudeney pattern types I, V, XI, and XII are not only valid for magic squares, but also for the magic tori that display these squares. On the other hand, the Dudeney pattern types II and III are shown to be partial viewpoints of a single pattern on the fourth-order magic tori. Again, the Dudeney pattern types IV and VI, the Dudeney pattern types VII and IX, and also the Dudeney pattern types VIII and X, are shown to be partial viewpoints of single patterns on the fourth-order magic tori.</div>
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We also notice that some of the detected complementary number patterns have contrasting hemitorus arrangements.<br />
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It is necessary to adapt the Dudeney pattern types, and add new symbols that not only reveal the real nature of the complementary number relationships, but also facilitate their comprehension. With this in mind, the 8 figures that follow have been selected to illustrate the essentially different complementary number pattern types that occur on fourth-order magic tori:</div>
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<a data-flickr-embed="true" href="https://www.flickr.com/photos/williwalk/48574092117/in/album-72157669867828824/" style="margin-left: 1em; margin-right: 1em;" title="Order_4_new_compl_number_pattern_types"><img alt="Magic Tori of Order-4 new complementary number pattern types" height="528" src="https://live.staticflickr.com/65535/48574092117_6d1cd16fdd_z.jpg" title="" width="323" /></a></div>
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To be read with a previous table that compared the 12 Dudeney pattern types with the 12 Magic torus types, published in <a href="https://carresmagiques.blogspot.com/2020/04/a-new-census-of-fourth-order-magic.html" target="_blank">"A New Census of Fourth-Order Magic Squares,"</a> the new table that follows, recapitulates the latest findings, and shows the repartition of the 8 complementary number patterns on the magic squares of the fourth-order magic tori:</div>
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<a data-flickr-embed="true" href="https://www.flickr.com/photos/williwalk/48568491676/in/album-72157669867828824/" title="Table_Compl_number_patterns_magic_tori_order_4"><img alt="Table of Complementary number patterns of magic tori of order-4" height="322" src="https://live.staticflickr.com/65535/48568491676_d5f24b4880_k.jpg" title="" width="525" /></a><script async="" charset="utf-8" src="//embedr.flickr.com/assets/client-code.js"></script><br />
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<u>Further Developments</u> </h2>
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New articles entitled <a href="https://carresmagiques.blogspot.com/2020/04/self-complementary-magic-tori-order-4.html" target="_blank">"Self-Complementary and Paired Complementary Magic Tori of Order-4"</a> and <a href="https://carresmagiques.blogspot.com/2020/04/multiplicative-magic-tori-and-magic-squares.html" target="_blank">"Multiplicative Magic Tori"</a> now extend the above findings.</div>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0tag:blogger.com,1999:blog-8742944687733483108.post-90217338712916112122016-03-27T20:06:00.004+02:002023-06-28T14:48:55.800+02:00First-Order Panmagic Torus T1<div style="text-align: justify;">
As is clearly stated in the <a href="https://oeis.org/A006052" target="_blank">OEIS sequence A006052</a><i> "Number of magic squares of order n composed of the numbers from 1 to n^2, counted up to rotations and reflections,"</i> the first and smallest magic square is of order-1.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5U0fjI85ql5QqsjY4xr3R9HkK6XHs7gq7Qt_mcsEIkPxmXgo3UrDUW3pJqxMlix8BK2slq3-rJotE03-eNS6eqJOwaOSNo24hX9LNiICvmV30laU71jYWjJWShtDAOQySjc2CUH3hxlo/s1600/T1.png" style="margin-left: 1em; margin-right: 1em;"><img alt="order-1 pandiagonal magic square or magic torus T1" border="0" data-original-height="260" data-original-width="500" height="53" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5U0fjI85ql5QqsjY4xr3R9HkK6XHs7gq7Qt_mcsEIkPxmXgo3UrDUW3pJqxMlix8BK2slq3-rJotE03-eNS6eqJOwaOSNo24hX9LNiICvmV30laU71jYWjJWShtDAOQySjc2CUH3hxlo/s200/T1.png" title="" width="100" /></a></div>
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The dotted red lines across this magic square represent its magic diagonals. For a basic magic square, each row, column, and main diagonal must sum to the magic constant. The magic constant of a magic square is equal to the division of the triangular number of its squared order by its order. The magic constant (mcN) of an Nth order magic square (or torus) can thus be calculated as follows:</div>
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mcN = <u>(N²)² + N²</u> x <u> 1 </u> = <u>N(N² + 1)</u></div>
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2 N 2</div>
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For the first-order magic square (or magic torus) the magic constant should therefore be: </div>
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mc1 = <u>1(1² + 1)</u> = 1, which is the case.</div>
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2</div>
The blue border of the unique number cell illustrated above, is also the limit of the magic square itself. <a href="https://www.youtube.com/watch?v=0H5_h-RB0T8&feature=youtu.be" rel="" target="_blank">The video below</a> shows how this blue border merges to form single latitude and longitude lines on the curved 2D surface of the first-order magic torus: </div>
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<iframe allowfullscreen="" frameborder="0" height="315" src="https://www.youtube.com/embed/0H5_h-RB0T8?rel=0&showinfo=0" width="420"></iframe> </div>
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<span style="font-size: xx-small;">Gluing a Torus video by <a href="https://youtu.be/0H5_h-RB0T8" target="_blank">Geometric Animations</a> - University of Hannover, <a href="https://developers.google.com/youtube/terms" target="_blank">hosted by YouTube</a> </span></div>
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We can check some of the simple conditions that define a basic magic odd-order torus, previously deduced whilst observing the unique <a href="http://carresmagiques.blogspot.fr/2012/01/255-fourth-order-magic-tori-and-1-third.html" target="_blank">third-order T3</a> magic torus:</div>
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<span lang="EN-GB" style="font-weight: normal; mso-ansi-language: EN-GB; text-decoration: none; text-underline: none;">The number of N-order squares (both magic and semi-magic squares) that are displayed on each N-order magic torus = N². The first-order magic torus should therefore display 1² = 1 first-order square, which is the case.</span></div>
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Basic magic odd-N-order tori display not only 1 basic N-order magic square, but also N²-1 semi-magic N-order squares. The first-order basic magic square should therefore display 1 basic order-1 magic square, and 1²-1 = 0 semi-magic order-1 squares, which is also the case.</div>
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<span lang="EN-GB" style="font-weight: normal; mso-ansi-language: EN-GB; text-decoration: none; text-underline: none;"><br />
</span> <span lang="EN-GB" style="font-weight: normal; mso-ansi-language: EN-GB; text-decoration: none; text-underline: none;">What is more surprising, although quite logical once we consider the question, is that the order-1 magic torus even satisfies the basic conditions for pandiagonality!</span></div>
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<span lang="EN-GB" style="font-weight: normal; mso-ansi-language: EN-GB; text-decoration: none; text-underline: none;"><br />
</span> <span lang="EN-GB" style="font-weight: normal; mso-ansi-language: EN-GB; text-decoration: none; text-underline: none;">If pandiagonal (magic along all of its diagonals), an N-order torus displays N² pandiagonal squares of order N. The first-order torus should therefore display 1² pandiagonal squares = 1 pandiagonal square, which once again is the case.</span></div>
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<span lang="EN-GB" style="font-weight: normal; mso-ansi-language: EN-GB; text-decoration: none; text-underline: none;"><span lang="EN-GB" style="font-weight: normal; mso-ansi-language: EN-GB; text-decoration: none; text-underline: none;">Taking into account the panmagic properties of this torus,</span> the adjective <i>"trivial,"</i> <a href="https://en.wikipedia.org/wiki/Magic_square" target="_blank">which is often used to describe the first-order square</a>, now seems almost depreciatory, (notwithstanding the fact that for mathematical contexts, the dictionary definitions o<span style="font-family: inherit;">f trivial</span> include: <i>"simple, transparent, or immediately evident"</i>). </span>T<span class="hvr">here is more to the order-1 torus than first meets the eye! Not only is it pandiagonal, but its number One also signifies mathematical creation and the very beginnings... The Pythagoreans referred to the number One as the "monad," which engendered the numbers, which engendered the point, which engendered all lines, etc. For Plotinus and other neoplatonists, the number One was the ultimate reality and the source of all existence. The first-order torus, together with the number One that it displays, both symbolise the "Big Bang."</span></div>
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<span class="hvr">I admit to having rather underestimated this first-order magic torus until <a href="http://www.region.com.ar/amela/franklinsquares/index.html" target="_blank">Miguel Angel Amela</a> kindly sent me a copy of one of his studies <i>"Pandiagonal Latin Squares and Latin Schemes in the Torus Surface,"</i> on the 9th March 2016. By extrapolating his findings, I discovered for myself the proof of the pandiagonal characteristics of the first-order, and I wish to thank Miguel for this paper which has been an inspiration to me.</span><br />
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<span class="hvr">The pandiagonal torus T1 of order-1 comes first again in the new <a href="https://oeis.org/A270876" target="_blank">OEIS sequence A270876</a> <i>"Number of magic tori of order n composed of the numbers from 1 to n^2."</i></span></div>
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<a href="https://follow.it/magic-squares-spheres-and-tori?leanpub" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="100" data-original-width="100" height="50" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg0vigrZezPCZZIGd9jhghwixsS9w07DNsnnMTZ1OxFNDyh_iaUlNrd2rzmljPhbDA-lW5aToN228hm43bfiM-GmLiDcip9gaKqQBe9UryfDqq3CV0UflNud24FtYvp7u5bQ_tSQyFcKrhmU-R6XUZ5D0_HV2sKKvyBCahvu9BxsTN2knCNPSttB8_NEY/w200-h200/10.png" width="50" /></a></div>William Walkingtonhttp://www.blogger.com/profile/02448010462310404797noreply@blogger.com0