A034755 Dirichlet convolution of 3^(n-1) with Catalan numbers.

1, 4, 11, 35, 95, 300, 861, 2658, 8009, 24668, 75845, 236401, 739453, 2338348, 7457697, 24047361, 78404391, 258796668, 865059189, 2929559709, 10050907467, 34926729660, 122863623249, 437203156566, 1572333684939, 5709236166372

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

Crossrefs

Sequence in context: A149235 A149236 A135919 * A297608 A034756 A029853

Adjacent sequences: A034752 A034753 A034754 * A034756 A034757 A034758

Keyword

nonn

Author

Erich Friedman

Status

approved