A034753 Dirichlet convolution of 3^(n-1) with sigma(n).

1, 6, 13, 43, 87, 294, 737, 2304, 6610, 19962, 59061, 178111, 531455, 1596558, 4783371, 14355733, 43046739, 129161004, 387420509, 1162321341, 3486787421, 10460530422, 31381059633, 94143721320, 282429536998, 847290203850

Offset

1,2

Links

Table of n, a(n) for n=1..26.

Formula

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

a(n) = Sum_{d|n} sigma(n/d)*3^(d-1). - Wesley Ivan Hurt, Dec 31 2023

Mathematica

Table[Sum[DivisorSigma[1, n/d]*3^(d - 1), {d, Divisors[n]}], {n, 1, 25}] (* Vaclav Kotesovec, Sep 10 2019 *)

Crossrefs

Cf. A000203.

Sequence in context: A216508 A057451 A239794 * A100905 A353964 A041489

Adjacent sequences: A034750 A034751 A034752 * A034754 A034755 A034756

Keyword

nonn

Author

Erich Friedman

Status

approved