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 A298964 #6 Jun 15 2020 14:02:15 %S A298964 1,8,219,21098,6892031,7785598672,30241030285680,403845370764198967, %T A298964 18541589058526001745929 %N A298964 Number of n X n 0..1 arrays with every element equal to 0, 1, 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero. %C A298964 Diagonal of A298970. %e A298964 Some solutions for n=5 %e A298964 ..0..0..0..0..0. .0..0..0..0..0. .0..0..0..0..0. .0..0..0..0..0 %e A298964 ..0..1..1..0..1. .0..0..0..1..0. .0..0..1..1..0. .0..0..1..0..0 %e A298964 ..0..0..1..0..0. .1..1..1..1..0. .1..1..0..1..0. .1..1..0..1..1 %e A298964 ..1..0..0..0..1. .1..0..0..0..1. .1..1..1..1..1. .0..1..0..1..1 %e A298964 ..1..1..1..1..0. .1..1..1..1..1. .0..1..0..0..1. .1..1..1..0..0 %Y A298964 Cf. A298970. %K A298964 nonn %O A298964 1,2 %A A298964 _R. H. Hardin_, Jan 30 2018