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 A266128 #4 Dec 21 2015 12:26:53 %S A266128 9,149,278,3851,62104,326145,4176690,50677045,367191341,4343077168, %T A266128 47557102126,393190838218,4413622529512,46442066137513, %U A266128 412349942225648,4457850641709751,46051121628392952,427183303899673724 %N A266128 Number of nX5 integer arrays with each element equal to the number of horizontal, diagonal and antidiagonal neighbors exactly one smaller than itself. %C A266128 Column 5 of A266131. %H A266128 R. H. Hardin, <a href="/A266128/b266128.txt">Table of n, a(n) for n = 1..210</a> %e A266128 Some solutions for n=4 %e A266128 ..1..1..0..0..1....2..1..2..0..0....0..0..1..2..0....1..0..2..1..0 %e A266128 ..1..0..2..1..1....0..1..2..3..0....1..2..3..2..1....0..1..1..3..2 %e A266128 ..0..2..2..2..2....1..2..2..0..1....0..1..3..0..0....1..1..1..1..2 %e A266128 ..0..0..1..1..0....1..0..0..1..1....2..1..1..2..1....1..0..1..1..0 %Y A266128 Cf. A266131. %K A266128 nonn %O A266128 1,1 %A A266128 _R. H. Hardin_, Dec 21 2015