A034774 Dirichlet convolution of d(n) (# of divisors) with Catalan numbers.

1, 3, 4, 10, 16, 52, 134, 446, 1437, 4896, 16798, 58896, 208014, 743170, 2674476, 9695727, 35357672, 129647751, 477638702, 1767272976, 6564120692, 24466300618, 91482563642, 343059732248, 1289904147355, 4861946817482

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[0, d], {d, Divisors[n]}], {n, 1, 25}] (* Vaclav Kotesovec, Sep 10 2019 *)

Crossrefs

Sequence in context: A081160 A051437 A224073 * A342536 A172416 A317883

Adjacent sequences: A034771 A034772 A034773 * A034775 A034776 A034777

Keyword

nonn

Author

Erich Friedman

Status

approved