A047940 Number of 5-colorings of an n X n grid, up to rotational symmetry.

1, 5, 165, 489125, 38147070625, 74505806274453125, 3637978807092666626953125, 4440892098500626236200333251953125, 135525271560688054250937420874834136962890625, 103397576569128459358926086520114040467888355255126953125

Offset: 0

Author

Rob Pratt

Keywords

• nonn

Links

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

Crossrefs

Column k=5 of A343095.

Cf. A054752, A047937.

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 = 5.

Extensions

Terms a(9) and beyond from Andrew Howroyd, Apr 14 2021