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 A302426 #4 Apr 07 2018 17:21:08 %S A302426 21,185,188,532,4223,14764,48037,227283,940829,3489620,14387459, %T A302426 59418248,233645986,941269019,3823009297,15290825815,61530089164, %U A302426 248256753643,996694292892,4011733223504,16159420719685,64946192160119 %N A302426 Number of nX7 0..1 arrays with every element equal to 0, 1, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302426 Column 7 of A302427. %H A302426 R. H. Hardin, <a href="/A302426/b302426.txt">Table of n, a(n) for n = 1..210</a> %e A302426 Some solutions for n=5 %e A302426 ..0..1..0..0..0..1..1. .0..0..1..0..1..0..1. .0..1..0..0..1..1..0 %e A302426 ..1..0..0..0..1..0..1. .1..1..1..0..1..0..0. .0..1..1..1..1..1..1 %e A302426 ..1..0..1..0..1..0..1. .1..0..1..0..1..0..1. .1..1..1..1..1..1..1 %e A302426 ..1..0..1..0..1..1..1. .1..0..0..0..1..0..1. .0..1..0..0..1..1..0 %e A302426 ..1..1..0..0..1..0..0. .0..1..0..0..0..1..1. .0..0..1..0..1..0..1 %Y A302426 Cf. A302427. %K A302426 nonn %O A302426 1,1 %A A302426 _R. H. Hardin_, Apr 07 2018