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 A268885 #4 Feb 15 2016 11:33:06 %S A268885 38,1340,42362,1187838,31427480,800733668,19876401224,483987898760, %T A268885 11611969197776,275345016177616,6466964539799840,150689548401385312, %U A268885 3487912674084234304,80273121207141357120,1838370376874099584640 %N A268885 Number of nX7 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once. %C A268885 Column 7 of A268886. %H A268885 R. H. Hardin, <a href="/A268885/b268885.txt">Table of n, a(n) for n = 1..210</a> %F A268885 Empirical: a(n) = 68*a(n-1) -1804*a(n-2) +24560*a(n-3) -195400*a(n-4) +974752*a(n-5) -3171360*a(n-6) +6871936*a(n-7) -9999248*a(n-8) +9740096*a(n-9) -6250176*a(n-10) +2552576*a(n-11) -621824*a(n-12) +79872*a(n-13) -4096*a(n-14) for n>16 %e A268885 Some solutions for n=3 %e A268885 ..1..0..0..0..0..0..0. .0..0..0..1..0..1..0. .0..0..0..1..0..1..1 %e A268885 ..0..1..1..0..0..0..0. .1..1..0..1..0..1..0. .1..0..0..0..0..0..0 %e A268885 ..0..0..0..1..0..0..1. .0..1..0..0..0..0..0. .0..0..0..0..0..0..0 %Y A268885 Cf. A268886. %K A268885 nonn %O A268885 1,1 %A A268885 _R. H. Hardin_, Feb 15 2016