A125427 Number of base 15 circular n-digit numbers with adjacent digits differing by 7 or less.

1, 15, 169, 1695, 19097, 219115, 2540413, 29568547, 344726553, 4021721265, 46932054649, 547742536301, 6392983509989, 74617206197211, 870919028712223, 10165247714847775, 118647535970217257, 1384840366115001717

Offset

0,2

Comments

[Empirical] a(base,n)=a(base-1,n)+F(7) for base>=7.int(n/2)+1 and F(d) is the largest coefficient in (1+x+...+x^(2d))^n

Links

Table of n, a(n) for n=0..17.

Prog

(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>7)+($[(i+1)mod N]`-$[i]`>7))

Crossrefs

Sequence in context: A201087 A138973 A016177 * A016279 A036734 A201041

Adjacent sequences: A125424 A125425 A125426 * A125428 A125429 A125430

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved