%I #11 Jun 04 2017 11:59:51

%S 1,11,115,1163,12199,128101,1345957,14142615,148604911,1561482659,

%T 16407457035,172403230769,1811546669413,19035033876467,

%U 200012796160859,2101657338173563,22083404921552671,232043903671421293

%N Number of base 11 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

%F G.f.: (1 - 3*x^2 - 46*x^3 + 3*x^4 + 28*x^5) / ((1 - x - x^2)*(1 - 10*x - 6*x^2 + 7*x^3)) (conjectured). - _Colin Barker_, Jun 04 2017

%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