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 A297229 #4 Dec 27 2017 15:41:42 %S A297229 1,189,1620,9861,171851,2063378,20599895,248421807,2936448567, %T A297229 33036817382,380933664485,4411216117906,50689193709680, %U A297229 583360678744857,6721605421544199,77399781711154720,891207805003409728 %N A297229 Number of 7Xn 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 1 neighboring 1s. %C A297229 Row 7 of A297224. %H A297229 R. H. Hardin, <a href="/A297229/b297229.txt">Table of n, a(n) for n = 1..210</a> %e A297229 Some solutions for n=5 %e A297229 ..0..0..0..0..0. .0..1..0..0..0. .0..0..0..1..1. .0..0..0..0..0 %e A297229 ..1..1..0..0..0. .1..0..0..1..1. .0..1..0..0..0. .0..0..0..0..0 %e A297229 ..0..1..1..0..0. .0..0..0..0..0. .1..0..1..0..0. .0..1..0..1..0 %e A297229 ..0..0..0..0..0. .0..0..0..0..0. .0..1..0..0..1. .1..0..1..0..0 %e A297229 ..0..0..0..0..0. .0..0..0..1..1. .0..0..0..1..0. .0..0..0..0..0 %e A297229 ..1..1..0..0..0. .0..0..0..0..0. .0..0..0..0..0. .0..0..1..0..0 %e A297229 ..0..0..0..1..1. .0..1..1..0..0. .0..0..0..1..1. .0..1..0..0..0 %Y A297229 Cf. A297224. %K A297229 nonn %O A297229 1,2 %A A297229 _R. H. Hardin_, Dec 27 2017