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 A269206 #4 Feb 20 2016 10:33:21 %S A269206 4096,1090740,142233732,19558138380,2532677348772,320994710282892, %T A269206 39825831571425924,4865841496644992100,587133256785089633172, %U A269206 70137053123425124078748,8308848756491598850682388 %N A269206 Number of 6Xn 0..3 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling three no more than once. %C A269206 Row 6 of A269201. %H A269206 R. H. Hardin, <a href="/A269206/b269206.txt">Table of n, a(n) for n = 1..210</a> %e A269206 Some solutions for n=2 %e A269206 ..0..1. .0..0. .0..1. .0..0. .0..0. .0..1. .0..1. .0..0. .0..1. .0..0 %e A269206 ..0..1. .0..0. .0..2. .2..0. .0..2. .0..0. .0..1. .0..1. .0..0. .0..0 %e A269206 ..1..0. .0..1. .3..1. .0..0. .3..2. .2..0. .3..1. .3..1. .2..0. .2..0 %e A269206 ..2..0. .0..2. .1..2. .1..0. .2..0. .0..0. .3..2. .3..3. .3..2. .2..3 %e A269206 ..1..3. .0..2. .2..3. .2..1. .2..3. .2..1. .2..0. .3..3. .2..2. .3..2 %e A269206 ..0..0. .2..3. .2..3. .3..2. .3..2. .1..0. .0..0. .2..3. .0..2. .0..3 %Y A269206 Cf. A269201. %K A269206 nonn %O A269206 1,1 %A A269206 _R. H. Hardin_, Feb 20 2016