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 A253160 #7 Jan 16 2024 10:27:57 %S A253160 558,5136,46752,443362,4189216,39478862,371551030,3500351616, %T A253160 32968666098,310607972526,2925948121986,27562007609152, %U A253160 259623715582126,2445694348190100,23038546105524370,217021887885861286 %N A253160 Number of (n+1) X (2+1) 0..2 arrays with every 2 X 2 subblock sum differing from its neighbors horizontally, vertically and nw-se diagonally. %C A253160 Column 2 of A253164. %H A253160 R. H. Hardin, <a href="/A253160/b253160.txt">Table of n, a(n) for n = 1..210</a> %e A253160 Some solutions for n=3 %e A253160 ..1..1..1....1..1..2....1..1..0....2..1..2....2..0..1....0..2..0....1..0..2 %e A253160 ..1..0..0....0..2..2....2..2..0....1..1..0....1..2..1....0..0..1....1..2..1 %e A253160 ..2..1..0....2..1..1....1..2..1....2..2..0....1..0..0....0..1..2....1..1..2 %e A253160 ..2..2..0....2..2..0....2..0..1....0..0..0....1..1..1....2..0..2....1..0..1 %Y A253160 Cf. A253164. %K A253160 nonn %O A253160 1,1 %A A253160 _R. H. Hardin_, Dec 28 2014