The hexagonal tortoise problem () was invented by Korean aristocrat and mathematician Choi Seok-jeong (1646–1715). It is a mathematical problem that involves a hexagonal lattice, like the hexagonal pattern on some tortoises' shells, to the (N) vertices of which must be assigned integers (from 1 to N) in such a way that the sum of all integers at the vertices of each hexagon is the same. The problem has apparent similarities to a magic square although it is a vertex-magic format rather than an edge-magic form or the more typical rows-of-cells form.
His book, Gusuryak, contains many mathematical discoveries. Related Problems Analogues of the hexagonal tortoise problem based on other Uniform tilings have also been studied. Yang Hui and Choi Seok-jeong studied related magic figures based on the truncated square tiling. Analogues based on the square tiling, in which the sums of the 2×2 subsquares are equal, have also been studied , as have analogues based on the trihexagonal tiling . References
See Also Magic hexagon Sources used