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 A125547 #6 Mar 31 2012 12:35:05 %S A125547 1,12,17782,3359860178,80173083905265254,241867388512389264991124102, %T A125547 92239510661284205765199147022065188442, %U A125547 4446848187806762069273466271591426934850445380022534 %N A125547 Number of n X n arrays with entries in 1..12 in which adjacent entries differ by 9 or less (adjacent means in x or y directions). %C A125547 [Empirical] a(base+1,n,diff) = a(base,n,diff)+F(n,diff) for base>=2.diff.(n-1) and F(n,diff) = (n = 2, A063496(diff+1)) (n = 3, A068744(diff+1)) (n = 4, A068745(diff+1)) (n = 5, A068746(diff+1)) (n = 6, A068747(diff+1)) %o A125547 (S/R) stvar $[N][N]:(0.. M-1) init $[][]:=0 asgn $[][]->{*} kill +[i in 0.. N-2](+[j in 0.. N-1](($[i][j]`-$[i+1][j]`>9)+($[i+1][j]`-$[i][j]`>9)+($[j][i]`-$[j][i+1]`>9)+($[j][i+1]`-$[j][i]`>9))) %K A125547 nonn %O A125547 0,2 %A A125547 _R. H. Hardin_, Dec 31 2006