A125330 Number of base 20 circular n-digit numbers with adjacent digits differing by 3 or less.

1, 20, 128, 656, 3928, 23840, 148304, 934968, 5958552, 38285216, 247607348, 1609914524, 10513615792, 68913452056, 453123210178, 2987405569166, 19741419610536, 130718419293680, 867078544410362, 5760352822741182

Offset

0,2

Comments

[Empirical] a(base,n)=a(base-1,n)+A025012(n+1) for base>=3.int(n/2)+1

Links

Table of n, a(n) for n=0..19.

Prog

(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>3)+($[(i+1)mod N]`-$[i]`>3))

Crossrefs

Sequence in context: A073968 A219710 A263229 * A126488 A304507 A005551

Adjacent sequences: A125327 A125328 A125329 * A125331 A125332 A125333

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved