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 A265872 #6 Aug 12 2016 06:53:59 %S A265872 24,984,56496,3965392,307543008,25346247472,2177808505472, %T A265872 192906735661528,17489278188423296,1614969746814390896, %U A265872 151358790056680049792,14360889227707270019712,1376684210617781240317184 %N A265872 Number of 4Xn arrays containing n copies of 0..4-1 with no element plus any antidiagonal neighbor equal to 4-1. %C A265872 Row 4 of A265870. %H A265872 R. H. Hardin, <a href="/A265872/b265872.txt">Table of n, a(n) for n = 1..33</a> %e A265872 Some solutions for n=3 %e A265872 ..1..0..3....2..3..0....1..2..2....1..0..2....3..2..2....2..0..3....3..1..2 %e A265872 ..2..3..2....2..1..0....0..0..2....1..2..3....2..0..3....0..2..1....1..0..2 %e A265872 ..2..0..3....3..0..1....0..3..1....0..2..3....0..1..1....3..0..1....0..0..3 %e A265872 ..1..1..0....2..3..1....1..3..3....0..3..1....1..0..3....1..3..2....2..3..1 %Y A265872 Cf. A265870. %K A265872 nonn %O A265872 1,1 %A A265872 _R. H. Hardin_, Dec 17 2015