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A034764 Dirichlet convolution of sigma(n) with Catalan numbers. 0
1, 4, 6, 15, 20, 64, 140, 466, 1451, 4928, 16808, 58986, 208026, 743328, 2674532, 9696213, 35357688, 129649324, 477638720, 1767277964, 6564120996, 24466317456, 91482563664, 343059792196, 1289904147439, 4861947025544 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

FORMULA

a(n) ~ 2^(2*n-2) / (sqrt(Pi) * n^(3/2)). - Vaclav Kotesovec, Sep 11 2019

MATHEMATICA

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

CROSSREFS

Sequence in context: A034771 A294457 A266883 * A119034 A100911 A346297

Adjacent sequences:  A034761 A034762 A034763 * A034765 A034766 A034767

KEYWORD

nonn

AUTHOR

Erich Friedman

STATUS

approved

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Last modified October 27 21:54 EDT 2021. Contains 348290 sequences. (Running on oeis4.)