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 A269093 #4 Feb 19 2016 09:48:05 %S A269093 108,11424,715320,37963968,1856325000,86415197088,3892946216856, %T A269093 171307237216320,7406621052177000,315868041326151072, %U A269093 13323538607075686392,556962735401445373632,23108630644746952831560 %N A269093 Number of nX4 0..3 arrays with some element plus some horizontally or vertically adjacent neighbor totalling three exactly once. %C A269093 Column 4 of A269097. %H A269093 R. H. Hardin, <a href="/A269093/b269093.txt">Table of n, a(n) for n = 1..210</a> %F A269093 Empirical: a(n) = 90*a(n-1) -2559*a(n-2) +24556*a(n-3) -94959*a(n-4) +140442*a(n-5) -69169*a(n-6) for n>7 %e A269093 Some solutions for n=2 %e A269093 ..1..1..1..2. .1..3..3..1. .0..1..0..0. .0..2..2..3. .1..0..1..0 %e A269093 ..0..1..0..2. .0..0..1..3. .2..3..2..1. .1..2..3..1. .3..2..1..1 %Y A269093 Cf. A269097. %K A269093 nonn %O A269093 1,1 %A A269093 _R. H. Hardin_, Feb 19 2016