A137334 Number of n X n crossword puzzles with dihedral symmetry group, for n odd. Acceptable crossword puzzles must have all words of length 3 or more, at least one word in each row and each column and be connected.
1, 2, 10, 45, 302, 3102, 45795
Offset: 3
Keywords
Examples
a(5) = 2 because, using 0's for white squares and 1's for black squares, the only two 5 X 5 puzzles with dihedral symmetry group are: 00000 00000 00000 00000 00000 and 10001 00000 00000 00000 10001
Links
- Marc Brodie, Mathematica program
Comments