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 A302375 #6 Sep 16 2020 18:55:13 %S A302375 0,3,76,4640,1089035,849467774,2195619257236,18920034863521166, %T A302375 543629426918828295527 %N A302375 Number of n X n 0..1 arrays with every element equal to 1, 2, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302375 Diagonal of A302381. %e A302375 Some solutions for n=5 %e A302375 ..0..0..0..0..0. .0..0..0..1..0. .0..0..0..0..0. .0..0..0..1..0 %e A302375 ..0..1..0..0..1. .0..0..0..0..1. .0..0..1..1..0. .0..1..1..0..1 %e A302375 ..0..0..1..1..1. .1..0..1..1..0. .1..0..0..0..0. .0..0..0..0..0 %e A302375 ..1..0..0..0..1. .1..1..0..0..0. .0..1..1..0..0. .1..1..0..1..0 %e A302375 ..0..1..0..0..0. .0..0..1..1..1. .1..0..1..1..1. .1..1..1..1..1 %Y A302375 Cf. A302381. %K A302375 nonn %O A302375 1,2 %A A302375 _R. H. Hardin_, Apr 06 2018