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 A268994 #4 Feb 17 2016 07:26:06 %S A268994 72,2037,57287,1506570,38241770,946498448,22995344760,550731432312, %T A268994 13040291111728,305911647779632,7121104059933536,164688437285444064, %U A268994 3787495455529375808,86684333527271203264,1975573336154420926848 %N A268994 Number of nX7 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once. %C A268994 Column 7 of A268995. %H A268994 R. H. Hardin, <a href="/A268994/b268994.txt">Table of n, a(n) for n = 1..210</a> %F A268994 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 A268994 Some solutions for n=3 %e A268994 ..0..0..0..1..0..0..0. .0..0..1..0..0..0..1. .1..0..0..0..1..0..1 %e A268994 ..0..0..0..0..0..0..0. .1..0..0..0..1..0..1. .0..0..1..0..0..0..0 %e A268994 ..0..1..1..0..1..0..0. .0..0..0..0..0..0..0. .1..0..0..0..1..0..0 %Y A268994 Cf. A268995. %K A268994 nonn %O A268994 1,1 %A A268994 _R. H. Hardin_, Feb 17 2016