A165872 Totally multiplicative sequence with a(p^e) = (-2)^e.

1, -2, -2, 4, -2, 4, -2, -8, 4, 4, -2, -8, -2, 4, 4, 16, -2, -8, -2, -8, 4, 4, -2, 16, 4, 4, -8, -8, -2, -8, -2, -32, 4, 4, 4, 16, -2, 4, 4, 16, -2, -8, -2, -8, -8, 4, -2, -32, 4, -8, 4, -8, -2, 16, 4, 16, 4, 4, -2, 16, -2, 4, -8, 64, 4, -8, -2, -8, 4, -8, -2, -32, -2, 4, -8, -8, 4, -8, -2, -32, 16, 4, -2, 16, 4, 4, 4, 16

Offset

1,2

Comments

The Dirichlet series is Product_{prime p} 1/(1+2/p^s), related to the Feller-Tornier constants like A065474. - R. J. Mathar, Feb 07 2011

Links

G. C. Greubel, Table of n, a(n) for n = 1..10000

Formula

a(n) = A122803(A001222(n)) = (-2)^bigomega(n) = (-2)^A001222(n).

Abs(a(n)) = A061142(n).

Mathematica

(-2)^PrimeOmega[Range[100]] (* G. C. Greubel, Apr 16 2016 *)

Prog

(PARI) a(n) = (-2)^bigomega(n); \\ Altug Alkan, Apr 16 2016

Crossrefs

Cf. A001222, A061142, A065474, A122803.

Sequence in context: A347958 A318316 A328721 * A061142 A318312 A318474

Adjacent sequences: A165869 A165870 A165871 * A165873 A165874 A165875

Keyword

sign,mult

Author

Jaroslav Krizek, Sep 28 2009

Status

approved