Soma cube cube problem. There are 240 distinct solutions of the Soma cube puzzle, excluding rotations and reflections: these are easily generated by a simple recursive backtracking search computer program similar to that used for the eight queens puzzle. Current world record for the fastest time to solve a soma cube is 2.93 seconds and was set by Krishnam Raju Gadiraju, India. The seven Soma pieces are six polycubes of order four, and one of order three: Piet Hein authorized a finely crafted rosewood version of the Soma cube manufactured by Theodor Skjøde Knudsen's company Skjøde Skjern (of Denmark). Beginning in about
Pantriagonal magic cube Pantriagonal magic cube A pantriagonal magic cube is a magic cube where all 4"m" pantriagonals sum correctly. There are 4 one-segment, 12("m" − 1) two-segment, and 4("m" − 2)("m" − 1) three-segment pantriagonals. This class of magic cubes may contain some simple magic squares and/or pandiagonal magic squares, but not enough to satisfy any other classifications. The constant for magic cubes is "S" = "m"("m" + 1)/2. A proper pantriagonal magic cube has 7"m" lines summing correctly. It contains "no" magic squares. Order 4 is the smallest pantriagonal magic cube possible. A pantriagonal magic cube is the 3-dimensional equivalent of