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 A297681 #4 Jan 03 2018 09:28:23 %S A297681 81,1632,52889,1519630,45865837,1368968852,41030621948,1229127412701, %T A297681 36837288191422,1103993847036050,33088254114520559,991712287397354032, %U A297681 29723613829882860702,890879134522839275761,26701570968782131551720 %N A297681 Number of nX7 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 1 or 4 neighboring 1s. %C A297681 Column 7 of A297682. %H A297681 R. H. Hardin, <a href="/A297681/b297681.txt">Table of n, a(n) for n = 1..210</a> %e A297681 Some solutions for n=3 %e A297681 ..1..0..0..0..0..0..1. .1..0..0..0..0..0..0. .0..0..0..0..1..0..0 %e A297681 ..1..0..1..0..0..0..0. .0..0..1..0..0..0..1. .1..0..0..0..0..0..1 %e A297681 ..1..1..1..0..1..0..1. .0..1..0..0..0..0..1. .0..0..0..1..1..0..0 %Y A297681 Cf. A297682. %K A297681 nonn %O A297681 1,1 %A A297681 _R. H. Hardin_, Jan 03 2018