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!)
A141668 a(n) = tau(n) * (NumberOfPartitions(n) - 1). 1
0, 0, 2, 4, 12, 12, 40, 28, 84, 87, 164, 110, 456, 200, 536, 700, 1150, 592, 2304, 978, 3756, 3164, 4004, 2508, 12592, 5871, 9740, 12036, 22302, 9128, 44824 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..5000

FORMULA

a(n) = A000005(n)*(A000041(n) - 1) = A000005(n)*A000065(n).

MATHEMATICA

f[n_] = DivisorSigma[0, n]*PartitionsP[n] - DivisorSigma[0, n]; Table[f[n], {n, 1, 30}]

PROG

(PARI) a(n) = if (n, numdiv(n)*(numbpart(n)-1), 0); \\ Michel Marcus, Jun 11 2018

CROSSREFS

Cf. A000005, A000041.

Sequence in context: A000348 A168342 A309515 * A087796 A268494 A306851

Adjacent sequences:  A141665 A141666 A141667 * A141669 A141670 A141671

KEYWORD

nonn

AUTHOR

Roger L. Bagula and Gary W. Adamson, Sep 06 2008

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 September 22 11:29 EDT 2020. Contains 337289 sequences. (Running on oeis4.)