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 A266104 #4 Dec 21 2015 08:22:52 %S A266104 1,39,230,929,6307,52171,371130,2568565,18322421,129531126,926299920, %T A266104 6712699992,48087248218,341400959047,2440466698929,17538694281014, %U A266104 125725413376414,899035671334963,6432936252126858,46077832832481217 %N A266104 Number of 4Xn integer arrays with each element equal to the number of horizontal and antidiagonal neighbors exactly one smaller than itself. %C A266104 Row 4 of A266101. %H A266104 R. H. Hardin, <a href="/A266104/b266104.txt">Table of n, a(n) for n = 1..210</a> %e A266104 Some solutions for n=4 %e A266104 ..1..0..0..0....1..0..1..1....0..1..2..0....1..0..1..1....0..0..1..1 %e A266104 ..0..0..0..0....1..1..0..1....2..1..1..2....0..2..0..1....1..1..0..0 %e A266104 ..0..0..0..0....2..1..2..0....0..2..1..1....1..0..2..1....1..0..0..1 %e A266104 ..0..0..0..1....1..0..0..0....0..0..0..1....0..0..0..0....1..2..1..0 %Y A266104 Cf. A266101. %K A266104 nonn %O A266104 1,2 %A A266104 _R. H. Hardin_, Dec 21 2015