Richard, supplemental information. If you plan to update problem D15 of UPINT, read my paper published in The Mathematical Intelligencer, Spring 2005, pages 52-64: I organized this paper around nine quotations from your own text, UPINT 3rd edition 2004. The 5x5x5 magic cube question is one of them (quotation #8, pages 60-62 of the M.I. paper). Christian. -----Message d'origine----- De : math-fun-bounces@mailman.xmission.com [mailto:math-fun-bounces@mailman.xmission.com] De la part de Richard Guy Envoyé : vendredi 7 mars 2008 17:36 À : Math Fun Objet : [math-fun] Magic cubes I have a question in UPINT, D15: ``Has anyone constructed a 5 x 5 x 5 magic cube, or proved its impossibility'' (just possibly asked by Rich Schroeppel?). I've recently downloaded a 2-page article by Maria'n Trenkler, An algorithm for making magic cubes, which was evidently published in Pi Mu Epsilon J, 12 #2 (Spring 2005) 105-106. It produces magic cubes of any order > 2. Am I the only person not to know about this? R. _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun