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 A295269 #7 Apr 19 2020 23:52:00 %S A295269 2,11,164,6659,748740,230659662,196091375073,458510348625561, %T A295269 2951683183977839155,52303382279027148884728, %U A295269 2551191530898428081696382880,342537007989863347885673784022387 %N A295269 Number of n X n 0..1 arrays with each 1 horizontally or vertically adjacent to 0, 1 or 4 1's. %C A295269 Diagonal of A295275. %H A295269 R. H. Hardin, <a href="/A295269/b295269.txt">Table of n, a(n) for n = 1..14</a> %e A295269 Some solutions for n=4 %e A295269 ..0..0..0..1....0..0..1..1....0..1..0..1....1..0..1..0....0..0..0..1 %e A295269 ..0..0..1..0....1..0..0..0....0..0..1..0....0..1..0..1....0..0..0..0 %e A295269 ..0..1..0..1....0..0..1..0....0..0..0..0....1..1..1..0....0..0..0..0 %e A295269 ..0..1..0..0....0..1..0..1....1..0..1..1....0..1..0..1....0..0..1..0 %Y A295269 Cf. A295275. %K A295269 nonn %O A295269 1,1 %A A295269 _R. H. Hardin_, Nov 19 2017