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A307425 Dirichlet g.f.: zeta(s) / (zeta(2*s) * zeta(3*s)). 1
1, 1, 1, 0, 1, 1, 1, -1, 0, 1, 1, 0, 1, 1, 1, -1, 1, 0, 1, 0, 1, 1, 1, -1, 0, 1, -1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, -1, 1, 1, 1, 0, 0, 1, 1, -1, 0, 0, 1, 0, 1, -1, 1, -1, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, -1, -1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1

COMMENTS

Dirichlet convolution of A212793 and A271102.

LINKS

Vaclav Kotesovec, Table of n, a(n) for n = 1..10000

Vaclav Kotesovec, Graph - the asymptotic ratio

Eric Weisstein's World of Mathematics, Dirichlet Generating Function

Wikipedia, Dirichlet series

FORMULA

Sum_{k=1..n} a(k) ~ 6*n / (Pi^2 * zeta(3)).

MATHEMATICA

nmax = 100; A271102 = Table[DivisorSum[n, Abs[MoebiusMu[#]]*MoebiusMu[n/#] &], {n, 1, nmax}]; Table[DivisorSum[n, Boole[Max[FactorInteger[#][[All, 2]]] < 3] * A271102[[n/#]] &], {n, 1, nmax}]

CROSSREFS

Cf. A056624, A210826, A212793, A271102, A299406.

Sequence in context: A255887 A295316 A014677 * A210826 A307421 A299406

Adjacent sequences:  A307422 A307423 A307424 * A307426 A307427 A307428

KEYWORD

sign,mult

AUTHOR

Vaclav Kotesovec, Apr 08 2019

STATUS

approved

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Last modified June 5 01:27 EDT 2020. Contains 334828 sequences. (Running on oeis4.)