%I #8 Mar 31 2012 12:35:02

%S 1,31,455,5503,77399,1110451,16305215,242704675,3649992607,

%T 55305511789,842747008815,12896518373649,197988896900735,

%U 3046905470601517,46975007273893153,725216490511279543,11207606597478569967

%N Number of base 31 circular n-digit numbers with adjacent digits differing by 8 or less.

%C [Empirical] a(base,n)=a(base-1,n)+F(8) for base>=8.int(n/2)+1 and F(d) is the largest coefficient in (1+x+...+x^(2d))^n

%o (S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>8)+($[(i+1)mod N]`-$[i]`>8))

%K nonn,base

%O 0,2

%A _R. H. Hardin_, Dec 28 2006