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 A297581 #4 Jan 01 2018 11:11:24 %S A297581 13,183,2085,20771,284289,3355439,38609160,476513137,5731862594, %T A297581 67900170433,820250735104,9868451991387,117996838335341, %U A297581 1418191530812586,17043255221943522,204368024253087875,2453682222488823920 %N A297581 Number of nX7 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 4 neighboring 1s. %C A297581 Column 7 of A297582. %H A297581 R. H. Hardin, <a href="/A297581/b297581.txt">Table of n, a(n) for n = 1..210</a> %e A297581 Some solutions for n=4 %e A297581 ..0..1..1..0..1..1..1. .1..0..0..0..1..0..1. .0..0..0..0..0..0..0 %e A297581 ..0..0..0..0..1..0..1. .0..1..0..0..1..1..0. .0..0..0..1..1..0..0 %e A297581 ..0..0..1..0..0..0..1. .0..0..0..0..0..0..1. .0..1..0..0..0..0..0 %e A297581 ..0..1..0..0..0..1..0. .0..0..0..1..1..0..0. .1..0..0..0..1..1..0 %Y A297581 Cf. A297582. %K A297581 nonn %O A297581 1,1 %A A297581 _R. H. Hardin_, Jan 01 2018