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 A295207 #6 Apr 26 2020 20:48:44 %S A295207 1,2,10,147,9536,1245294,444447937,436106162865,1123957773816109, %T A295207 7694570450089060470,140076394691747502547476 %N A295207 Number of n X n 0..1 arrays with each 1 horizontally or vertically adjacent to 2 or 3 1's. %C A295207 Diagonal of A295213. %e A295207 Some solutions for n=5 %e A295207 ..1..1..1..0..0. .0..1..1..1..0. .0..0..0..1..1. .0..0..0..0..0 %e A295207 ..1..0..1..1..0. .1..1..0..1..1. .1..1..0..1..1. .0..0..1..1..1 %e A295207 ..1..1..0..1..1. .1..1..0..0..1. .1..1..1..1..0. .1..1..1..0..1 %e A295207 ..0..1..0..0..1. .0..1..1..1..1. .1..0..0..1..0. .1..1..1..0..1 %e A295207 ..0..1..1..1..1. .0..1..1..0..0. .1..1..1..1..0. .0..0..1..1..1 %Y A295207 Cf. A295213. %K A295207 nonn %O A295207 1,2 %A A295207 _R. H. Hardin_, Nov 17 2017