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 A300805 #6 Aug 20 2020 11:39:26 %S A300805 1,8,170,9504,1415898,559634028,585611214958,1623186113355468, %T A300805 11918444465082418938,231853794250990035322072 %N A300805 Number of n X n 0..1 arrays with every element equal to 0, 1, 2, 3 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. %C A300805 Diagonal of A300811. %e A300805 Some solutions for n=5 %e A300805 ..0..0..0..0..0. .0..0..0..0..0. .0..0..0..0..0. .0..0..0..0..0 %e A300805 ..1..1..1..0..1. .0..1..1..0..1. .1..0..1..1..0. .0..1..1..1..0 %e A300805 ..1..0..1..0..1. .0..0..1..0..0. .0..1..0..1..1. .1..0..0..0..1 %e A300805 ..0..0..0..1..0. .1..0..1..1..1. .0..0..0..1..0. .0..1..0..1..0 %e A300805 ..1..1..1..1..0. .0..0..1..0..0. .0..0..1..0..1. .1..1..0..0..1 %Y A300805 Cf. A300811. %K A300805 nonn %O A300805 1,2 %A A300805 _R. H. Hardin_, Mar 13 2018