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 A268884 #4 Feb 15 2016 11:32:21 %S A268884 20,475,9996,186732,3283890,55491832,911930096,14681855846, %T A268884 232688402028,3642322709900,56444213311842,867475989937560, %U A268884 13239446101273360,200865483664370358,3031934392327858732,45561723449682618252 %N A268884 Number of nX6 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once. %C A268884 Column 6 of A268886. %H A268884 R. H. Hardin, <a href="/A268884/b268884.txt">Table of n, a(n) for n = 1..210</a> %F A268884 Empirical: a(n) = 42*a(n-1) -665*a(n-2) +5138*a(n-3) -21972*a(n-4) +55274*a(n-5) -83769*a(n-6) +76202*a(n-7) -40273*a(n-8) +11304*a(n-9) -1296*a(n-10) for n>12 %e A268884 Some solutions for n=4 %e A268884 ..1..0..0..0..0..0. .0..0..0..1..1..0. .1..0..0..0..1..1. .1..0..1..0..0..1 %e A268884 ..0..0..1..0..0..1. .0..1..0..0..0..1. .0..0..0..0..0..1. .0..0..1..0..0..1 %e A268884 ..1..0..0..1..0..1. .0..1..0..0..0..0. .1..0..1..0..0..0. .1..0..1..0..0..0 %e A268884 ..1..1..0..1..0..1. .0..0..0..0..0..0. .0..0..1..0..1..0. .0..1..0..0..0..1 %Y A268884 Cf. A268886. %K A268884 nonn %O A268884 1,1 %A A268884 _R. H. Hardin_, Feb 15 2016