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 A302531 #4 Apr 09 2018 09:27:26 %S A302531 0,61,497,902,3683,23909,128242,465323,1918153,10153650,48825739, %T A302531 206962001,913773720,4366054069,20367538805,90798363146,409867362675, %U A302531 1900191504221,8749921654714,39674026618581,180520404483627 %N A302531 Number of 5Xn 0..1 arrays with every element equal to 1, 2, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302531 Row 5 of A302528. %H A302531 R. H. Hardin, <a href="/A302531/b302531.txt">Table of n, a(n) for n = 1..210</a> %e A302531 Some solutions for n=5 %e A302531 ..0..1..1..1..1. .0..0..1..1..1. .0..1..1..0..0. .0..1..0..1..1 %e A302531 ..0..0..0..0..0. .0..1..1..0..1. .1..0..0..1..1. .1..0..0..0..1 %e A302531 ..0..1..0..1..0. .0..1..0..1..0. .1..0..1..0..1. .0..1..0..1..0 %e A302531 ..1..0..0..0..1. .1..0..0..1..0. .0..1..1..0..0. .1..0..0..0..1 %e A302531 ..0..1..0..1..0. .0..1..1..0..1. .1..0..0..1..1. .1..1..0..1..1 %Y A302531 Cf. A302528. %K A302531 nonn %O A302531 1,2 %A A302531 _R. H. Hardin_, Apr 09 2018