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A307425
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Dirichlet g.f.: zeta(s) / (zeta(2*s) * zeta(3*s)).
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2
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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
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OFFSET
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1
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COMMENTS
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Dirichlet convolution of A212793 and A271102.
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LINKS
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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
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FORMULA
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Sum_{k=1..n} a(k) ~ 6*n / (Pi^2 * zeta(3)).
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MATHEMATICA
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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}]
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PROG
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(PARI) for(n=1, 100, print1(direuler(p=2, n, (1+X)*(1-X^3))[n], ", ")) \\ Vaclav Kotesovec, Jun 14 2020
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CROSSREFS
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Cf. A056624, A210826, A212793, A271102, A299406.
Sequence in context: A255887 A295316 A014677 * A210826 A307421 A299406
Adjacent sequences: A307422 A307423 A307424 * A307426 A307427 A307428
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KEYWORD
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sign,mult
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AUTHOR
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Vaclav Kotesovec, Apr 08 2019
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STATUS
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approved
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