Some October news from www.multimagie.com/indexengl.htm: -Best known 6x6 pandiagonal multiplicative magic square, first seen in [math-fun]. 5 720 160 45 80 1440 4800 12 150 192 300 6 9 400 288 25 144 800 320 180 10 2880 20 90 75 48 2400 3 1200 96 576 100 18 1600 36 50 And other new best known nxn pandiag mult squares. -Nobody knows a 4x4 magic square of cubes, using distinct positive integers. But very interesting step with the first known 4x4 semi-magic squares of cubes (semi-magic means non-magic diagonals), by Lee Morgenstern, USA 16^3 20^3 18^3 192^3 180^3 81^3 90^3 15^3 108^3 135^3 150^3 9^3 2^3 160^3 144^3 24^3 Who will construct a 4x4 magic square of cubes, with 2 magic diagonals? -you will see nice construction methods of 4x4 (used for the above square), 6x6, 8x8, 9x9 semi-magic squares of nth-powers, using Taxicab numbers. I am not sure that magic squares are useful, and not sure that Taxicab numbers are useful, ...but good news: Taxicab numbers are at least useful for magic squares! Christian.