A125456 - OEIS

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

%S 1,21,285,3333,44589,609441,8484027,119207781,1683956109,23857954869,

%T 338563579455,4808766812871,68334330572247,971314874179749,

%U 13808436456553037,196319581589707923,2791268881281069805

%N Number of base 21 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