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A034719
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Dirichlet convolution of powers of 3 (3,9,27,...) with themselves.
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1
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9, 54, 162, 567, 1458, 4860, 13122, 40824, 118827, 358668, 1062882, 3206142, 9565938, 28737180, 86106564, 258404985, 774840978, 2324916594, 6973568802, 20921808654, 62762237316, 188289546300, 564859072962, 1694587257216
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OFFSET
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1,1
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LINKS
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Table of n, a(n) for n=1..24.
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FORMULA
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a(n) ~ 2 * 3^(n+1). - Vaclav Kotesovec, Sep 11 2019
G.f.: Sum_{k>=1} 3^(k+1)*x^k / (1 - 3*x^k). - Ilya Gutkovskiy, Sep 22 2020
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MATHEMATICA
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Table[Sum[3^(d + n/d), {d, Divisors[n]}], {n, 1, 30}] (* Vaclav Kotesovec, Sep 11 2019 *)
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CROSSREFS
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Equals 9 * A034751(n).
Sequence in context: A225791 A093846 A152994 * A013567 A073974 A223927
Adjacent sequences: A034716 A034717 A034718 * A034720 A034721 A034722
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KEYWORD
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nonn
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AUTHOR
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Erich Friedman
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STATUS
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approved
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