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 A265865 #6 Aug 12 2016 06:53:59 %S A265865 8,384,22016,1584088,124214208,10318543104,891453176832, %T A265865 79282110189528,7210026166925504,667397938420086784, %U A265865 62673274464982136832,5956095271996318830016,571751372700932605781504 %N A265865 Number of 4Xn arrays containing n copies of 0..4-1 with no element plus any vertical neighbor equal to 4-1. %C A265865 Row 4 of A265863. %H A265865 R. H. Hardin, <a href="/A265865/b265865.txt">Table of n, a(n) for n = 1..39</a> %e A265865 Some solutions for n=3 %e A265865 ..2..3..2....3..3..0....1..1..3....0..2..3....3..0..1....1..2..2....3..1..1 %e A265865 ..0..1..0....1..2..2....0..0..1....2..0..1....2..1..3....1..3..3....3..1..3 %e A265865 ..1..1..2....0..0..3....2..2..3....3..1..0....2..1..3....0..3..1....2..0..2 %e A265865 ..0..3..3....1..2..1....2..0..3....3..1..2....0..0..2....0..2..0....2..0..0 %Y A265865 Cf. A265863. %K A265865 nonn %O A265865 1,1 %A A265865 _R. H. Hardin_, Dec 17 2015