Excellent column, and proud to see my name! Ed, I was not aware that you planned to write a column on the subject, I worked without informing you on my latest results. Main recent results: 1) Yes, additive-multiplicative magic squares are improvable. I have examples of 8x8 and 9x9 additive-multiplicative magic squares with smaller constants than the previously known examples http://mathworld.wolfram.com/Addition-MultiplicationMagicSquare.html (40 times smaller for the 8x8 square) 2) Probably the smallest possible example of 11x11 pandiagonal multiplicative magic square. Ed (or others), I can send you Excel files including these squares, if you are interested. Let me know. And thanks for your mention of my 100$ prize + bottle of Champagne. Who will win the prize? Christian. -----Message d'origine----- De : math-fun-bounces+cboyer=club-internet.fr@mailman.xmission.com [mailto:math-fun-bounces+cboyer=club-internet.fr@mailman.xmission.com] De la part de ed pegg Envoyé : lundi 14 novembre 2005 21:15 À : math-fun Objet : [math-fun] Multiplicative magic squares I've summarized many of the posts and discoveries here about Multiplicative Magic Squares in my latest maa.org column http://www.maa.org/editorial/mathgames/mathgames_11_07_05.html Ed Pegg Jr _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun