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 A302454 #6 Sep 16 2020 18:55:56 %S A302454 1,2,18,10,924,5266,404761,26036557,4110999261,1386699669527 %N A302454 Number of n X n 0..1 arrays with every element equal to 0, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302454 Diagonal of A302460. %e A302454 Some solutions for n=5 %e A302454 ..0..1..0..0..1. .0..1..0..1..1. .0..1..1..0..1. .0..1..1..0..1 %e A302454 ..1..1..1..0..0. .1..1..1..1..1. .0..1..1..0..1. .0..1..1..0..1 %e A302454 ..0..1..1..0..0. .0..1..0..0..0. .0..1..0..0..0. .0..1..0..0..0 %e A302454 ..1..1..1..0..0. .0..1..1..0..1. .1..1..1..0..0. .0..1..1..0..1 %e A302454 ..0..1..0..0..1. .1..1..1..0..1. .1..1..0..0..0. .1..1..1..0..1 %Y A302454 Cf. A302460. %K A302454 nonn %O A302454 1,2 %A A302454 _R. H. Hardin_, Apr 08 2018