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 A268771 #4 Feb 13 2016 08:25:56 %S A268771 96,248,1524,10340,64112,387146,2258084,12951796,73011192,406925194, %T A268771 2244513800,12281806624,66734787464,360505595710,1937557458852, %U A268771 10367717536488,55261185262316,293537189567482,1554428843176696 %N A268771 Number of nX5 0..2 arrays with some element plus some horizontally, vertically, diagonally or antidiagonally adjacent neighbor totalling two exactly once. %C A268771 Column 5 of A268774. %H A268771 R. H. Hardin, <a href="/A268771/b268771.txt">Table of n, a(n) for n = 1..210</a> %F A268771 Empirical: a(n) = 4*a(n-1) +28*a(n-2) -62*a(n-3) -314*a(n-4) +78*a(n-5) +867*a(n-6) +6*a(n-7) -859*a(n-8) +46*a(n-9) +215*a(n-10) -8*a(n-11) -16*a(n-12) for n>14 %e A268771 Some solutions for n=4 %e A268771 ..1..2..1..2..2. .2..1..2..1..2. .0..0..1..1..0. .2..2..1..2..1 %e A268771 ..2..2..2..2..2. .2..1..2..2..2. .0..0..0..0..0. .2..2..2..2..2 %e A268771 ..1..2..2..2..1. .2..2..2..2..2. .0..1..0..1..0. .2..1..2..2..2 %e A268771 ..2..2..2..2..1. .2..2..2..2..1. .0..0..0..0..0. .2..2..1..2..1 %Y A268771 Cf. A268774. %K A268771 nonn %O A268771 1,1 %A A268771 _R. H. Hardin_, Feb 13 2016