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 A302874 #4 Apr 15 2018 10:32:16 %S A302874 8,31,72,306,1197,4849,23037,114810,603229,3319946,18585700,105379875, %T A302874 603107047,3467522323,19998520262,115602617979,669078024352, %U A302874 3875760664026,22464758703891,130258464383067,755475828119163 %N A302874 Number of nX5 0..1 arrays with every element equal to 0, 1, 3, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302874 Column 5 of A302877. %H A302874 R. H. Hardin, <a href="/A302874/b302874.txt">Table of n, a(n) for n = 1..210</a> %e A302874 Some solutions for n=5 %e A302874 ..0..1..0..1..0. .0..1..1..0..0. .0..1..0..1..1. .0..1..0..0..0 %e A302874 ..0..0..1..1..0. .1..1..1..1..1. .0..1..1..0..1. .1..1..0..1..0 %e A302874 ..0..1..0..1..0. .1..1..1..0..1. .1..0..1..0..1. .1..1..1..1..0 %e A302874 ..0..1..0..1..0. .0..1..1..0..1. .1..0..1..0..1. .1..1..0..0..0 %e A302874 ..0..1..1..0..0. .0..1..0..1..1. .1..1..1..0..1. .0..1..0..1..0 %Y A302874 Cf. A302877. %K A302874 nonn %O A302874 1,1 %A A302874 _R. H. Hardin_, Apr 15 2018