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 A269275 #4 Feb 21 2016 08:56:56 %S A269275 5832,9211608,9230973192,7934992835112,6310088238337128, %T A269275 4786284820998999528,3516906597130333936872,2525822328725627338344168, %U A269275 1783069155917082001205203176,1241926797984458949166277812968 %N A269275 Number of nX7 0..3 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling three exactly once. %C A269275 Column 7 of A269276. %H A269275 R. H. Hardin, <a href="/A269275/b269275.txt">Table of n, a(n) for n = 1..210</a> %F A269275 Empirical: a(n) = 1384*a(n-1) -566002*a(n-2) +61993580*a(n-3) -3083170217*a(n-4) +82564587476*a(n-5) -1288497445564*a(n-6) +12048887832352*a(n-7) -66380108132464*a(n-8) +198314583195456*a(n-9) -247475435747904*a(n-10) for n>11 %e A269275 Some solutions for n=2 %e A269275 ..0..0..0..1..3..1..2. .0..0..1..0..0..1..1. .0..0..0..0..0..1..2 %e A269275 ..2..0..0..1..3..2..2. .0..0..1..0..1..1..2. .0..0..2..2..0..0..0 %Y A269275 Cf. A269276. %K A269275 nonn %O A269275 1,1 %A A269275 _R. H. Hardin_, Feb 21 2016