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A034713 Dirichlet convolution of powers of 2 (2,4,8,...) with themselves. 0
4, 16, 32, 80, 128, 320, 512, 1152, 2112, 4352, 8192, 17152, 32768, 66560, 131584, 264448, 524288, 1053696, 2097152, 4203520, 8390656, 16793600, 33554432, 67147776, 134218752, 268500992, 536879104, 1073876992, 2147483648 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..29.

FORMULA

a(n) = 4 * A034733(n).

G.f.: Sum_{k>=1} 2^(k+1)*x^k/(1 - 2*x^k). - Ilya Gutkovskiy, Sep 10 2019

a(n) ~ 2^(n+2). - Vaclav Kotesovec, Sep 11 2019

MATHEMATICA

Table[Sum[2^(d + n/d), {d, Divisors[n]}], {n, 1, 30}] (* Vaclav Kotesovec, Sep 11 2019 *)

PROG

(PARI) a(n) = if(n==0, 1, sumdiv(n, d, 2^d * 2^(n/d) )); \\ Joerg Arndt, Apr 14 2013

CROSSREFS

Cf. A000079, A034733.

Sequence in context: A326873 A126032 A296819 * A101653 A043100 A329853

Adjacent sequences:  A034710 A034711 A034712 * A034714 A034715 A034716

KEYWORD

nonn

AUTHOR

Erich Friedman

STATUS

approved

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Last modified March 8 11:41 EST 2021. Contains 341948 sequences. (Running on oeis4.)