OFFSET
1,4
FORMULA
Multiplicative with a(p^e) = e*(-1)^e, p prime and e > 0.
Dirichlet g.f.: (zeta(2*s))^2 / (zeta(s)*zeta(3*s)).
Dirichlet inverse b(n), n>=1, is multiplicative with b(1)=1 and for p prime and e>0: b(p^e) = 0 if e mod 3 = 0 otherwise b(p^e) = (-1)^(3 - e mod 3).
MATHEMATICA
Array[LiouvilleLambda[#] Apply[Times, FactorInteger[#][[All, -1]] ] &, 83] (* Michael De Vlieger, May 06 2018 *)
PROG
(PARI) a(n) = (-1)^bigomega(n)*factorback(factor(n)[, 2]); \\ Michel Marcus, May 05 2018
CROSSREFS
KEYWORD
sign,easy,mult
AUTHOR
Werner Schulte, May 02 2018
STATUS
approved