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 A269041 #4 Feb 18 2016 09:05:06 %S A269041 0,25272,357756,8277072,159397596,3266423688,63310818360, %T A269041 1232016734502,23480085224460,445037745455958,8347562556153996, %U A269041 155656709783860410,2883687582601214532,53163977044543395168,975616567564729165860 %N A269041 Number of 7Xn 0..2 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once. %C A269041 Row 7 of A269035. %H A269041 R. H. Hardin, <a href="/A269041/b269041.txt">Table of n, a(n) for n = 1..210</a> %H A269041 R. H. Hardin, <a href="/A269041/a269041.txt">Empirical recurrence of order 92</a> %F A269041 Empirical recurrence of order 92 (see link above) %e A269041 Some solutions for n=2 %e A269041 ..0..0. .1..2. .2..2. .0..0. .1..2. .1..0. .1..0. .1..2. .1..0. .2..2 %e A269041 ..1..1. .1..2. .2..1. .1..0. .2..2. .0..2. .1..0. .1..0. .1..0. .2..1 %e A269041 ..2..2. .1..0. .0..1. .1..2. .2..1. .1..0. .0..0. .1..2. .2..2. .0..1 %e A269041 ..2..1. .0..1. .0..0. .2..0. .0..2. .1..2. .1..2. .2..2. .2..2. .2..1 %e A269041 ..2..2. .0..1. .0..0. .1..2. .2..1. .1..0. .1..0. .1..0. .2..1. .1..2 %e A269041 ..2..1. .0..1. .1..0. .2..2. .2..2. .1..2. .0..0. .1..2. .2..2. .1..0 %e A269041 ..2..1. .0..1. .2..2. .2..1. .2..2. .1..0. .0..1. .2..2. .2..2. .0..0 %Y A269041 Cf. A269035. %K A269041 nonn %O A269041 1,2 %A A269041 _R. H. Hardin_, Feb 18 2016