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A160956 a(n) = ((2^b-1)/phi(n))*Sum_{d|n} Moebius(n/d)*d^(b-1) for b = 9. 1
511, 130305, 1676080, 16679040, 49902216, 427400400, 490968800, 2134917120, 3665586960, 12725065080, 10953738768, 54707251200, 34736533160, 125197044000, 163679268480, 273269391360, 222788253240, 934724674800 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..5000

J. H. Kwak and J. Lee, Enumeration of graph coverings, surface branched coverings and related group theory, in Combinatorial and Computational Mathematics (Pohang, 2000), ed. S. Hong et al., World Scientific, Singapore 2001, pp. 97-161. See p. 134.

FORMULA

a(n) = 511*A160908(n). - R. J. Mathar, Mar 16 2016

MATHEMATICA

A160956[n_] := DivisorSum[n, MoebiusMu[n/#]*#^(9 - 1)/EulerPhi[n] &]; Table[511*A160956[n], {n, 1, 50}] (* G. C. Greubel, Dec 12 2017 *)

CROSSREFS

Sequence in context: A258810 A321554 A321548 * A022191 A069384 A069410

Adjacent sequences:  A160953 A160954 A160955 * A160957 A160958 A160959

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Nov 19 2009

STATUS

approved

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Last modified January 17 23:37 EST 2020. Contains 330995 sequences. (Running on oeis4.)