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 A293094 #6 Apr 06 2020 00:39:23 %S A293094 0,0,48,8088,3125547,5589631828,38469698642410,1110306381675662688 %N A293094 Number of n X n 0..1 arrays with the number of 1's horizontally, diagonally or antidiagonally adjacent to some 0 two less than the number of 0's adjacent to some 1. %C A293094 Diagonal of A293100. %e A293094 Some solutions for n=4 %e A293094 ..1..1..1..0. .0..0..0..0. .0..0..0..0. .1..1..0..1. .1..1..0..1 %e A293094 ..0..1..0..1. .1..1..1..0. .0..0..0..1. .0..0..0..0. .0..0..1..0 %e A293094 ..0..0..0..0. .1..0..0..0. .1..0..0..1. .0..1..1..0. .1..0..0..0 %e A293094 ..0..0..1..1. .0..1..1..1. .1..0..1..0. .1..0..1..0. .0..0..0..0 %Y A293094 Cf. A293100. %K A293094 nonn %O A293094 1,3 %A A293094 _R. H. Hardin_, Sep 30 2017