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A320091 Number of primitive (=aperiodic) 7-ary words with length less than or equal to n which are earlier in lexicographic order than any other word derived by cyclic shifts of the alphabet. 3
1, 7, 55, 391, 2791, 19543, 137191, 960391, 6725143, 47076343, 329551591, 2306861191, 16148148391, 113037041143, 791260111543, 5538820797943, 38771751367543, 271402259573191, 1899815857483639, 13298711002502839, 93090977299997143, 651636841100805895 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..1184

FORMULA

a(n) = Sum_{j=1..n} Sum_{d|j} 7^(d-1) * mu(j/d).

a(n) = A143327(n,7).

a(n) = Sum_{j=1..n} A143325(j,7).

a(n) = A143326(n,7) / 7.

MAPLE

b:= n-> add(`if`(d=n, 7^(n-1), -b(d)), d=numtheory[divisors](n)):

a:= proc(n) option remember; b(n)+`if`(n<2, 0, a(n-1)) end:

seq(a(n), n=1..30);

CROSSREFS

Column k=7 of A143327.

Partial sums of A320072.

Cf. A008683, A143325, A143326.

Sequence in context: A217327 A069404 A198689 * A172743 A015564 A070997

Adjacent sequences:  A320088 A320089 A320090 * A320092 A320093 A320094

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Oct 05 2018

STATUS

approved

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Last modified November 16 19:17 EST 2019. Contains 329201 sequences. (Running on oeis4.)