A125477 - OEIS

A125477

Number of base 20 circular n-digit numbers with adjacent digits differing by 9 or less.

1, 20, 290, 3710, 53630, 790670, 11804384, 177140396, 2664526934, 40121436206, 604415162550, 9107184376046, 137237515952000, 2068136987970632, 31166901568081520, 469690150305370760, 7078330364431520854

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OFFSET

0,2

COMMENTS

[Empirical] a(base,n)=a(base-1,n)+F(9) for base>=9.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]`-$[(i+1)mod N]`>9)+($[(i+1)mod N]`-$[i]`>9))

CROSSREFS

Sequence in context: A225829 A017918 A329710 * A016261 A016309 A190824

Adjacent sequences: A125474 A125475 A125476 * A125478 A125479 A125480

KEYWORD

nonn,base

AUTHOR

R. H. Hardin, Dec 28 2006

STATUS

approved