A167531 a(n) = Sum_{d divides n} d*(n/d)^(d-1).

1, 3, 4, 9, 6, 25, 8, 49, 37, 101, 12, 373, 14, 477, 496, 1313, 18, 3907, 20, 6941, 5272, 11309, 24, 49321, 3151, 53301, 59320, 144789, 30, 468181, 32, 657473, 649936, 1114181, 121416, 5124961, 38, 4980813, 6909280, 13756761, 42, 44768725, 44

Offset

1,2

Links

Seiichi Manyama, Table of n, a(n) for n = 1..5000

Formula

G.f.: Sum{k>0} x^k/(1-k*x^k)^2.

Prog

(PARI) a(n)=sumdiv(n, d, d*(n/d)^(d-1))
(PARI) N=66; x='x+O('x^N); Vec(sum(k=1, N, x^k/(1-k*x^k)^2)) \\ Seiichi Manyama, Sep 03 2019

Crossrefs

Cf. A055225, A324158.

Sequence in context: A264786 A055225 A054791 * A344195 A376683 A356541

Adjacent sequences: A167528 A167529 A167530 * A167532 A167533 A167534

Keyword

nonn

Author

Franklin T. Adams-Watters, Nov 05 2009

Status

approved