A141668 a(n) = tau(n) * (NumberOfPartitions(n) - 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

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: A309515 A342311 A358502 * 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