A125447 - OEIS

%I #14 Jul 18 2017 01:46:12

%S 1,12,132,1380,15260,169252,1879782,20881502,231972500,2577002988,

%T 28628206202,318033966218,3533075401202,39249335918974,

%U 436025331971998,4843854954088810,53810935050499732,597791791563925916

%N Number of base 12 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.: (1-6*x^2-88*x^3+15*x^4+128*x^5-5*x^6-36*x^7) / ((1-2*x-x^2+x^3)*(1-10*x-13*x^2+7*x^3+6*x^4)) (conjectured). - _Colin Barker_, Jul 17 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