Mathematical Recreations & Essays

alphabet Archimedean solids arithmetic arrangement Bidder Bisect calculating centre cipher circle colours column construction containing corresponding counters cryptanalyst cube cyclical permutation D. H. Lehmer denote described determined diagonal diagram digits digraphs discs districts divided dodecahedron dominoes edges equal equivalent Euler's faces Fermat's figure four geometrical girls give given Hence hexagons icosahedron instance integers KLMN L. E. Dickson letters lines London magic square Mathematical Messenger of Mathematics method move multiple n² cells obtained octahedron odd nodes pack pairs pandiagonal pawns pentagon Petrie polygon pieces pile places of decimals plain-text plane polygon polyhedra polyhedron position possible prime problem queens re-entrant rectangle regular regular polygons result rhombicuboctahedron right angles ring route rule selected card sides solution solved steps suffixes suppose symmetrical tessellation tetrahedra theorem triangles triplets vertex vertices