A034719 Dirichlet convolution of powers of 3 (3,9,27,...) with themselves.

9, 54, 162, 567, 1458, 4860, 13122, 40824, 118827, 358668, 1062882, 3206142, 9565938, 28737180, 86106564, 258404985, 774840978, 2324916594, 6973568802, 20921808654, 62762237316, 188289546300, 564859072962, 1694587257216

Offset

1,1

Links

Table of n, a(n) for n=1..24.

Formula

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

Mathematica

Table[Sum[3^(d + n/d), {d, Divisors[n]}], {n, 1, 30}] (* Vaclav Kotesovec, Sep 11 2019 *)

Crossrefs

Equals 9 * A034751(n).

Sequence in context: A225791 A093846 A152994 * A013567 A073974 A223927

Adjacent sequences: A034716 A034717 A034718 * A034720 A034721 A034722

Keyword

nonn

Author

Erich Friedman

Status

approved