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 A207867 #7 Mar 11 2023 20:14:11 %S A207867 15,10900,68162042,1625686993918,103204230192540988, %T A207867 14231913620170652461908,3737733535781386231895815398, %U A207867 1704434626479905430949721771156450,1259921002642906004433313180012192804586,1431587436371216664854796169984729275373681588 %N A207867 Number of n X 5 nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal or vertical neighbor (colorings ignoring permutations of colors). %H A207867 Andrew Howroyd, <a href="/A207867/b207867.txt">Table of n, a(n) for n = 1..100</a> %e A207867 Some solutions for n=5 %e A207867 ..0..1..0..1..0....0..1..0..1..0....0..1..0..1..0....0..1..0..1..0 %e A207867 ..1..0..1..0..1....1..0..1..0..1....2..0..1..0..1....1..0..1..0..1 %e A207867 ..0..1..0..1..0....0..1..0..1..0....0..1..0..1..0....0..1..0..1..0 %e A207867 ..1..0..1..0..1....2..0..1..0..1....1..0..1..2..1....1..2..1..0..1 %e A207867 ..0..1..0..1..0....0..1..0..1..0....0..1..0..1..0....0..1..0..1..0 %Y A207867 Column 5 of A207868. %K A207867 nonn %O A207867 1,1 %A A207867 _R. H. Hardin_, Feb 21 2012 %E A207867 Terms a(6) and beyond from _Andrew Howroyd_, Mar 11 2023