The original Panex puzzle is from the Japanese Magic Company from the 1980's. Mathematicians at Bell Laboratories estimated the number of moves to swap 2 columns of order 10 to be 27,564 <= N <= 31,537. It came in two varieties: one with a blue and a yellow pyramid of order 10 on silver tiles; in the gold version pieces of each color look alike i.e. no pyramid is drawn on them), this is a little harder. The original Tower of Hanoi puzzle is the invention of Edouard Lucas and was sold as a toy in France in 1883. The legend of 64 disks in the great temple of Benares of the god Brahma is also his invention. WWW: http://www.tux.org/~bagleyd/puzzles.html