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 A302802 #6 Sep 16 2020 18:59:11 %S A302802 1,8,169,8718,1089773,327603711,238687785290,420681832487223, %T A302802 1791195821074091291 %N A302802 Number of n X n 0..1 arrays with every element equal to 0, 1, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302802 Diagonal of A302808. %e A302802 Some solutions for n=5 %e A302802 ..0..0..0..0..0. .0..0..0..0..0. .0..0..0..0..1. .0..0..0..0..1 %e A302802 ..0..1..1..1..1. .0..1..1..0..0. .1..1..1..1..0. .0..0..1..1..1 %e A302802 ..1..1..1..0..0. .1..0..0..1..0. .0..0..0..0..1. .1..0..1..0..1 %e A302802 ..0..1..0..1..1. .0..0..1..1..0. .0..1..1..0..0. .0..1..1..0..1 %e A302802 ..0..1..1..0..0. .0..0..1..1..1. .1..1..1..1..0. .0..0..0..1..1 %Y A302802 Cf. A302808. %K A302802 nonn %O A302802 1,2 %A A302802 _R. H. Hardin_, Apr 13 2018