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 A126527 #7 Mar 31 2012 12:35:06
%S A126527 1,32,268,2292,19748,170904,1483284,12899556,112350184,979640156,
%T A126527 8549531716,74665238648,652426700120,5703387501520,49875030912772,
%U A126527 436266613941484,3816936851122500,33400491065984904,292314430831005104
%N A126527 Number of base 32 n-digit numbers with adjacent digits differing by four or less.
%C A126527 [Empirical] a(base,n)=a(base-1,n)+9^(n-1) for base>=4n-3; a(base,n)=a(base-1,n)+9^(n-1)-2 when base=4n-4
%o A126527 (S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>4)+($[i+1]`-$[i]`>4))
%Y A126527 Cf. Base 32 differing by three or less A126500, two or less A126419, one or less A126386.
%K A126527 nonn,base
%O A126527 0,2
%A A126527 _R. H. Hardin_, Dec 28 2006