OFFSET
1,1
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Michel Marcus, Table of n, a(n) for n = 1..10000
N. J. A. Sloane, Transforms
FORMULA
G.f.: Sum_{n>=1} a(n)*x^n/(1 - x^n) = Sum_{n>=1} prime(n)*x^n. - Ilya Gutkovskiy, Apr 25 2017
a(n) = Sum_{d|n} prime(d)*mu(n/d), where mu is the Moebius function (A008683). - Wesley Ivan Hurt, Sep 23 2020
MATHEMATICA
a[n_] := DivisorSum[n, Prime[#] * MoebiusMu[n/#] &]; Array[a, 200] (* Enrique Pérez Herrero, Sep 23 2020 *)
PROG
(PARI) a(n) = sumdiv(n, d, prime(d)*moebius(n/d)); \\ Michel Marcus, Nov 04 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved