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 A269199 #4 Feb 20 2016 10:27:18 %S A269199 2592,472044,84310620,13753913556,2135938293684,320994710282892, %T A269199 47121391706947500,6796525936086462132,966936595386067680804, %U A269199 136062368474581143710892,18974537404982889834704892 %N A269199 Number of nX6 0..3 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling three no more than once. %C A269199 Column 6 of A269201. %H A269199 R. H. Hardin, <a href="/A269199/b269199.txt">Table of n, a(n) for n = 1..210</a> %H A269199 R. H. Hardin, <a href="/A269199/a269199.txt">Empirical recurrence of order 42</a> %F A269199 Empirical recurrence of order 42 (see link above) %e A269199 Some solutions for n=2 %e A269199 ..0..0..0..2..0..1. .0..0..1..3..1..3. .0..3..2..0..0..2. .0..2..0..2..2..2 %e A269199 ..0..0..2..0..2..2. .2..0..2..1..1..3. .2..0..2..0..0..0. .0..1..0..0..3..3 %Y A269199 Cf. A269201. %K A269199 nonn %O A269199 1,1 %A A269199 _R. H. Hardin_, Feb 20 2016