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 A268808 #6 Feb 13 2016 18:25:53 %S A268808 768,4914,48460,640926,8734264,115671422,1508087180,19390335102, %T A268808 246666802206,3110082281974,38924665296474,484120668061458, %U A268808 5988867204857378,73740656947715536,904257358969806890 %N A268808 Number of nX7 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once. %C A268808 Column 7 of A268809. %H A268808 R. H. Hardin, <a href="/A268808/b268808.txt">Table of n, a(n) for n = 1..210</a> %H A268808 R. H. Hardin, <a href="/A268808/a268808.txt">Empirical recurrence of order 68</a> %F A268808 Empirical recurrence of order 68 (see link above) %e A268808 Some solutions for n=3 %e A268808 ..2..2..2..2..2..1..2. .0..0..0..1..0..0..0. .0..0..1..0..1..0..0 %e A268808 ..2..2..2..2..2..2..1. .0..0..0..0..1..0..1. .1..0..0..1..0..0..1 %e A268808 ..1..2..1..2..1..0..0. .0..1..0..0..0..0..1. .0..1..0..0..1..0..0 %Y A268808 Cf. A268809. %K A268808 nonn %O A268808 1,1 %A A268808 _R. H. Hardin_, Feb 13 2016