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 A303039 #4 Apr 17 2018 13:22:59 %S A303039 21,363,360,2926,11079,59654,345668,2060154,13122422,89037375, %T A303039 632329265,4677904112,35799149696,280072132889,2226022479526, %U A303039 17895152751103,144903511517451,1178993189869482,9624601342853800,78735791021587131 %N A303039 Number of nX7 0..1 arrays with every element equal to 0, 1, 3, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A303039 Column 7 of A303040. %H A303039 R. H. Hardin, <a href="/A303039/b303039.txt">Table of n, a(n) for n = 1..210</a> %e A303039 Some solutions for n=5 %e A303039 ..0..1..1..1..1..1..0. .0..1..1..1..0..1..0. .0..1..0..0..0..0..1 %e A303039 ..1..1..1..1..0..1..0. .0..1..0..1..0..1..1. .0..0..0..0..0..1..0 %e A303039 ..0..1..0..1..0..1..0. .0..1..0..1..0..1..0. .0..1..0..0..0..1..0 %e A303039 ..1..1..0..1..0..1..0. .0..1..0..0..0..1..0. .0..1..0..0..0..0..0 %e A303039 ..0..1..0..1..1..0..0. .1..0..0..0..0..0..0. .0..0..0..0..0..1..0 %Y A303039 Cf. A303040. %K A303039 nonn %O A303039 1,1 %A A303039 _R. H. Hardin_, Apr 17 2018