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 A266135 #4 Dec 21 2015 12:32:18 %S A266135 1,189,2099,4336,62104,1285961,16386099,124675418,1670106261, %T A266135 27030614673,364728678843,4110151431884,55582288536407, %U A266135 820578817704699,11258792567726911,142486826279283951,1934013157303232327 %N A266135 Number of 5Xn integer arrays with each element equal to the number of horizontal, diagonal and antidiagonal neighbors exactly one smaller than itself. %C A266135 Row 5 of A266131. %H A266135 R. H. Hardin, <a href="/A266135/b266135.txt">Table of n, a(n) for n = 1..83</a> %e A266135 Some solutions for n=4 %e A266135 ..2..1..1..1....1..0..0..1....1..2..1..1....1..0..1..2....2..1..0..1 %e A266135 ..2..1..0..0....1..1..1..1....0..0..0..1....2..1..1..2....2..1..1..0 %e A266135 ..1..3..2..0....1..1..1..1....0..2..1..1....0..1..2..2....2..3..2..2 %e A266135 ..0..0..2..1....1..0..0..2....1..2..2..1....2..2..1..2....0..1..1..2 %e A266135 ..0..0..0..1....0..2..1..1....0..0..0..0....0..1..1..0....1..0..1..2 %Y A266135 Cf. A266131. %K A266135 nonn %O A266135 1,2 %A A266135 _R. H. Hardin_, Dec 21 2015