Dürer's 1514 square from "Melencolia I" (National Gallery of Victoria) |
Suzanne Alejandre, at Math Forum, Drexel University, publishes contributions from Allan Adler and many other magic square specialists.
Harvey Heinz is greatly missed since he passed away in 2013, but his site continues to give us much useful information.
Mutsumi Suzuki retired in 2001. His pages used to be available at Math Forum, Drexel University. Unfortunately, since their site was reorganised, the access has become difficult. Today it is simpler to use http://web.archive.org (as above).