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 A297538 #6 May 03 2020 15:32:26 %S A297538 1,2,35,275,12161,3015179,1610981344,1479214192234,4028895802966726, %T A297538 43695679891258322395 %N A297538 Number of n X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 3 neighboring 1's. %C A297538 Diagonal of A297544. %e A297538 Some solutions for n=5 %e A297538 ..0..0..0..0..0. .1..1..0..1..1. .0..0..0..1..1. .0..1..1..0..0 %e A297538 ..0..0..0..1..0. .1..1..0..1..1. .1..1..0..1..1. .1..1..0..1..1 %e A297538 ..0..0..1..1..1. .1..1..0..1..0. .1..1..0..0..0. .0..0..0..1..1 %e A297538 ..1..1..0..0..0. .1..0..0..1..1. .0..0..0..1..0. .1..1..0..0..1 %e A297538 ..0..1..1..0..0. .0..1..1..1..1. .0..0..1..1..1. .1..1..1..1..0 %Y A297538 Cf. A297544. %K A297538 nonn %O A297538 1,2 %A A297538 _R. H. Hardin_, Dec 31 2017