A034741 Dirichlet convolution of mu(n) with 3^(n-1).

1, 2, 8, 24, 80, 232, 728, 2160, 6552, 19600, 59048, 176880, 531440, 1593592, 4782880, 14346720, 43046720, 129133368, 387420488, 1162241760, 3486783664, 10460294152, 31381059608, 94142999520, 282429536400, 847288078000, 2541865821768, 7625595890640, 22876792454960

Offset

1,2

Links

Seiichi Manyama, Table of n, a(n) for n = 1..2096

Formula

G.f.: Sum_{k>=1} mu(k)*x^k/(1 - 3*x^k). - Ilya Gutkovskiy, Oct 25 2018

a(n) ~ 3^(n-1). - Vaclav Kotesovec, Sep 11 2019

Mathematica

nmax = 20; Rest[CoefficientList[Series[Sum[MoebiusMu[k] * x^k / (1 - 3*x^k), {k, 1, nmax}], {x, 0, nmax}], x]] (* Vaclav Kotesovec, Dec 11 2020 *)

Prog

(PARI) a(n) = sumdiv(n, d, moebius(d) * 3^(n/d-1) ); \\ Joerg Arndt, Apr 14 2013

Crossrefs

Column k=3 of A143325.

First differences of A320087.

Cf. A054718.

Sequence in context: A228404 A006952 A327550 * A063727 A085449 A127362

Adjacent sequences: A034738 A034739 A034740 * A034742 A034743 A034744

Keyword

nonn

Author

Erich Friedman

Status

approved