This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A047940 #9 Apr 14 2021 22:27:57 %S A047940 1,5,165,489125,38147070625,74505806274453125, %T A047940 3637978807092666626953125,4440892098500626236200333251953125, %U A047940 135525271560688054250937420874834136962890625,103397576569128459358926086520114040467888355255126953125 %N A047940 Number of 5-colorings of an n X n grid, up to rotational symmetry. %H A047940 Andrew Howroyd, <a href="/A047940/b047940.txt">Table of n, a(n) for n = 0..25</a> %F A047940 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. %Y A047940 Column k=5 of A343095. %Y A047940 Cf. A054752, A047937. %K A047940 nonn %O A047940 0,2 %A A047940 _Rob Pratt_ %E A047940 Terms a(9) and beyond from _Andrew Howroyd_, Apr 14 2021