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 A230062 #8 Jun 02 2025 08:40:28 %S A230062 0,9,45,15129,14082255,114228452529,5392746297039195, %T A230062 1669550033290419884241,3264068813720842706362349013, %U A230062 40741287160388602906800646716513609 %N A230062 Number of n X n 0..2 arrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value 2-x(i,j). %C A230062 Diagonal of A230068 %H A230062 R. H. Hardin, <a href="/A230062/b230062.txt">Table of n, a(n) for n = 1..12</a> %e A230062 Some solutions for n=4 %e A230062 ..2..1..1..1....0..2..2..2....2..0..2..1....2..1..1..0....1..0..0..1 %e A230062 ..1..0..1..1....0..2..0..0....2..0..1..2....1..0..2..1....2..1..1..2 %e A230062 ..1..0..2..1....2..0..2..2....0..1..0..1....2..0..1..2....2..2..1..0 %e A230062 ..2..1..1..0....2..0..2..0....1..2..1..2....2..0..0..1....0..0..2..1 %K A230062 nonn %O A230062 1,2 %A A230062 _R. H. Hardin_, Oct 08 2013