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 A302732 #4 Apr 12 2018 10:57:17 %S A302732 0,421,4064,3316,17828,104969,532511,1932168,7608792,40495097, %T A302732 193959222,806044112,3571553560,16732139668,77717205902,345532208087, %U A302732 1548242747664,7108827463856,32520170426142,146833013273650,664181788383321 %N A302732 Number of 7Xn 0..1 arrays with every element equal to 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302732 Row 7 of A302728. %H A302732 R. H. Hardin, <a href="/A302732/b302732.txt">Table of n, a(n) for n = 1..210</a> %e A302732 Some solutions for n=5 %e A302732 ..0..0..0..0..0. .0..0..1..1..0. .0..0..1..0..0. .0..0..1..1..0 %e A302732 ..1..1..1..1..1. .1..0..0..0..1. .1..1..0..1..1. .1..0..0..0..0 %e A302732 ..0..0..0..0..0. .0..1..0..0..0. .1..0..1..0..1. .1..1..1..0..0 %e A302732 ..0..1..0..1..0. .0..0..1..1..0. .1..0..1..0..1. .0..0..1..1..0 %e A302732 ..0..1..1..1..1. .1..0..0..0..1. .0..1..0..1..0. .1..0..1..0..1 %e A302732 ..0..0..0..0..0. .0..1..0..0..0. .1..0..1..0..1. .1..1..1..0..0 %e A302732 ..0..1..1..1..1. .0..0..0..1..1. .0..1..0..1..0. .0..0..0..1..1 %Y A302732 Cf. A302728. %K A302732 nonn %O A302732 1,2 %A A302732 _R. H. Hardin_, Apr 12 2018