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 A239159 #6 Jul 23 2025 10:58:14 %S A239159 340,17050,2709568,330311070,42600989632,5427557363908, %T A239159 693325664438772,88515970694682238,11302116207196944184, %U A239159 1443066224926757673588,184253299972460754777622,23525764336051214515515358 %N A239159 Number of (6+1)X(n+1) 0..3 arrays with no element equal to all horizontal neighbors or unequal to all vertical neighbors, and new values 0..3 introduced in row major order. %C A239159 Row 6 of A239155 %H A239159 R. H. Hardin, <a href="/A239159/b239159.txt">Table of n, a(n) for n = 1..154</a> %e A239159 Some solutions for n=2 %e A239159 ..0..1..2....0..1..0....0..1..0....0..1..2....0..1..2....0..1..0....0..1..2 %e A239159 ..0..1..2....0..1..0....0..1..0....0..1..2....0..1..2....0..1..0....0..1..2 %e A239159 ..2..3..1....2..3..0....2..3..0....2..3..2....1..0..3....0..1..0....0..2..1 %e A239159 ..2..3..1....2..3..2....2..3..0....2..3..2....1..0..3....2..1..2....1..2..1 %e A239159 ..0..3..1....2..3..2....2..1..2....2..1..2....1..2..3....2..1..2....1..2..1 %e A239159 ..0..3..2....1..0..2....3..1..2....0..1..0....3..2..1....3..1..3....1..3..0 %e A239159 ..0..3..2....1..0..2....3..1..2....0..1..0....3..2..1....3..1..3....1..3..0 %K A239159 nonn %O A239159 1,1 %A A239159 _R. H. Hardin_, Mar 11 2014