A047944 Number of 9-colorings of an n X n grid, up to rotational symmetry.

1, 9, 1665, 96870249, 463255057977921, 179474496923598616041129, 5632099886234793640483695986653185, 14316042242555870306568544190208626253583093449, 2947546144434645792880218215353988087374626027116634833972481

Offset

0,2

Links

Andrew Howroyd, Table of n, a(n) for n = 0..25

Formula

a(n) = (m^(n^2) + 2 m^((n^2 + 3 (n mod 2))/4) + m^((n^2 + (n mod 2))/2))/4, with m = 9.

Crossrefs

Column k=9 of A343095.

Cf. A047937.

Sequence in context: A381197 A197206 A197804 * A322245 A381269 A251700

Adjacent sequences: A047941 A047942 A047943 * A047945 A047946 A047947

Keyword

nonn

Author

Rob Pratt

Extensions

Terms a(8) and beyond from Andrew Howroyd, Apr 14 2021

Status

approved