A034717 Dirichlet convolution of Catalan numbers (1,2,5,14...) with themselves.

1, 4, 10, 32, 84, 284, 858, 2916, 9749, 33760, 117572, 416692, 1485800, 5350596, 19390110, 70721256, 259289580, 955298168, 3534526380, 13128309200, 48932538330, 182965362424, 686119227300, 2579809144692, 9723892804668

Offset

1,2

Links

Table of n, a(n) for n=1..25.

Formula

a(n) ~ 2^(2*n+1) / (sqrt(Pi) * n^(3/2)). - Vaclav Kotesovec, Sep 11 2019

Mathematica

Table[Sum[CatalanNumber[n/d]*CatalanNumber[d], {d, Divisors[n]}], {n, 1, 30}] (* Vaclav Kotesovec, Sep 10 2019 *)

Crossrefs

Sequence in context: A360919 A015796 A318562 * A295404 A001673 A017936

Adjacent sequences: A034714 A034715 A034716 * A034718 A034719 A034720

Keyword

nonn

Author

Erich Friedman

Status

approved