%I #8 Mar 31 2012 12:35:02
%S 1,27,387,4635,64275,910047,13176603,193286799,2861938467,42649954911,
%T 638456984747,9587390463271,144280174667379,2174497641266991,
%U 32806154775168315,495286442631446295,7481115443229599555
%N Number of base 27 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