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 A297588 #4 Jan 01 2018 11:17:15 %S A297588 1,178,3854,17549,171543,3230902,38609160,348140132,4059598106, %T A297588 52019909493,586271189408,6378535786438,74263762213809, %U A297588 871302311717772,9894632611196172,112311237616769754,1295286294924141697 %N A297588 Number of 7Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 4 neighboring 1s. %C A297588 Row 7 of A297582. %H A297588 R. H. Hardin, <a href="/A297588/b297588.txt">Table of n, a(n) for n = 1..210</a> %e A297588 Some solutions for n=5 %e A297588 ..0..0..1..0..0. .0..0..1..0..0. .0..0..0..1..1. .0..0..0..0..1 %e A297588 ..0..0..0..1..0. .0..0..0..1..0. .0..0..0..0..0. .1..1..0..1..0 %e A297588 ..0..0..0..0..0. .0..0..0..0..0. .0..1..0..1..0. .0..0..0..0..0 %e A297588 ..1..0..0..0..0. .0..1..0..1..0. .0..1..1..0..0. .0..0..1..1..0 %e A297588 ..1..1..1..0..0. .0..0..1..1..0. .0..1..0..0..1. .0..0..0..0..0 %e A297588 ..1..0..0..0..0. .0..1..0..0..0. .0..0..0..1..1. .1..0..0..1..0 %e A297588 ..0..0..0..0..0. .0..0..0..1..1. .0..0..1..0..1. .0..1..0..0..1 %Y A297588 Cf. A297582. %K A297588 nonn %O A297588 1,2 %A A297588 _R. H. Hardin_, Jan 01 2018