login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A034716 Dirichlet convolution of factorials with themselves. 0
1, 4, 12, 52, 240, 1464, 10080, 80736, 725796, 7258080, 79833600, 958006368, 12454041600, 174356602560, 2615348737440, 41845579937856, 711374856192000, 12804747412916160, 243290200817664000, 4865804016367800960, 102181884343418940480, 2248001455555375027200 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..22.

FORMULA

a(n) ~ 2 * n!. - Vaclav Kotesovec, Jan 28 2019

MATHEMATICA

Table[Sum[d!*(n/d)!, {d, Divisors[n]}], {n, 1, 25}] (* Vaclav Kotesovec, Jan 28 2019 *)

PROG

(PARI) a(n)=sumdiv(n, d, (d!) * (n/d)! );  /* Joerg Arndt, Oct 07 2012 */

CROSSREFS

Sequence in context: A188230 A124006 A215524 * A129841 A277431 A065525

Adjacent sequences:  A034713 A034714 A034715 * A034717 A034718 A034719

KEYWORD

nonn

AUTHOR

Erich Friedman

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 8 11:34 EST 2021. Contains 341948 sequences. (Running on oeis4.)