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 A125543 #6 Mar 31 2012 12:35:05 %S A125543 1,10,8022,543128374,3055705944761702,1431275227278696138328486, %T A125543 55801019314977359729825524189282042, %U A125543 181083160867536477536139285619272596798948123330 %N A125543 Number of n X n arrays with entries in 1..10 in which adjacent entries differ by 7 or less (adjacent means in x or y directions). %C A125543 [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 A125543 (S/R) stvar $[N][N]:(0.. M-1) init $[][]:=0 asgn $[][]->{*} kill +[i in 0.. N-2](+[j in 0.. N-1](($[i][j]`-$[i+1][j]`>7)+($[i+1][j]`-$[i][j]`>7)+($[j][i]`-$[j][i+1]`>7)+($[j][i+1]`-$[j][i]`>7))) %K A125543 nonn %O A125543 0,2 %A A125543 _R. H. Hardin_, Dec 31 2006