login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A028342 Expansion of prod( (1-x^i)^(-1/i), i = 1..infinity); also of exp(sum( d(n)*x^n /n, n = 1..infinity)) where d is number of divisors function. 3
1, 1, 3, 11, 59, 339, 2629, 20677, 202089, 2066201, 24322931, 296746251, 4193572723, 59806188571, 954679763829, 15845349818789, 285841314451409, 5293203821406897, 106976406006818659, 2201383054398314251 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

LINKS

N. J. A. Sloane, Transforms

FORMULA

This is an expansion as an exponential generating function; i.e., as sum a(n)*x^n/n!.

Equivalently, a(n)/n! is the Euler transform of [1,1/2,1/3,1/4,...].

CROSSREFS

Cf. A000005.

Sequence in context: A137690 A107007 A156560 * A137982 A074509 A112368

Adjacent sequences:  A028339 A028340 A028341 * A028343 A028344 A028345

KEYWORD

nonn

AUTHOR

Jeffrey Shallit (shallit(AT)graceland.uwaterloo.ca)

EXTENSIONS

Edited by Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Jul 03 2009

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 21:45 EST 2012. Contains 205978 sequences.