A125407 - OEIS

A125407

Number of base 19 circular n-digit numbers with adjacent digits differing by 6 or less.

1, 19, 205, 1867, 19609, 210299, 2304745, 25570683, 286088961, 3218305099, 36333221305, 411138068195, 4659331066705, 52854308911787, 599940896079401, 6812571733982387, 77379505012100545, 879048702969334779

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OFFSET

0,2

COMMENTS

[Empirical] a(base,n)=a(base-1,n)+F(6) for base>=6.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.

OEIS Wiki, Number of base k circular n-digit numbers with adjacent digits differing by d or less

Rafał Wiktorowicz, Proofs of the conjectured recurrences and generating functions for the adjacent-digits family, 2026.

Index entries for linear recurrences with constant coefficients, signature (19,-78,-182,896,728,-3192,-1248,4968,1040,-3776,-416,1376,64,-192).

PROG

(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>6)+($[(i+1)mod N]`-$[i]`>6))

CROSSREFS

Sequence in context: A085770 A002501 A180364 * A289423 A278556 A023017

Adjacent sequences: A125404 A125405 A125406 * A125408 A125409 A125410

KEYWORD

nonn,base

AUTHOR

R. H. Hardin, Dec 28 2006

STATUS

approved