A125430 Number of base 18 circular n-digit numbers with adjacent digits differing by 7 or less.

1, 18, 214, 2202, 25862, 310258, 3787948, 46645456, 577150510, 7159272162, 88927443434, 1105386497794, 13745406254372, 170957599435056, 2126500579257954, 26452521788330842, 329064936891773982

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..16.

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: A021804 A025932 A260569 * A021764 A059357 A324638

Adjacent sequences: A125427 A125428 A125429 * A125431 A125432 A125433

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved