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 A297725 #4 Jan 04 2018 22:02:52 %S A297725 1,876,21116,268630,6812856,183324631,4021047904,89397422003, %T A297725 2107800484124,48991993784653,1122852568198335,25900643054077073, %U A297725 599236232228096280,13831438744530944473,319108863737459622613 %N A297725 Number of 6Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1, 2 or 4 neighboring 1s. %C A297725 Row 6 of A297720. %H A297725 R. H. Hardin, <a href="/A297725/b297725.txt">Table of n, a(n) for n = 1..210</a> %e A297725 Some solutions for n=3 %e A297725 ..0..1..0. .0..1..1. .0..1..1. .0..0..1. .0..0..0. .0..0..1. .0..1..0 %e A297725 ..0..0..1. .1..1..0. .1..0..0. .1..1..1. .0..1..0. .1..1..0. .1..1..0 %e A297725 ..0..0..0. .1..0..1. .1..1..1. .0..0..1. .1..0..0. .0..0..0. .0..0..0 %e A297725 ..1..0..0. .0..1..0. .0..1..1. .0..1..0. .0..0..0. .1..1..0. .0..1..1 %e A297725 ..0..1..1. .0..0..0. .1..0..0. .0..1..1. .1..0..0. .1..1..0. .1..0..0 %e A297725 ..0..0..0. .1..1..1. .1..1..0. .1..0..0. .1..1..0. .0..0..0. .0..0..0 %Y A297725 Cf. A297720. %K A297725 nonn %O A297725 1,2 %A A297725 _R. H. Hardin_, Jan 04 2018