OFFSET
1,9
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
FORMULA
MATHEMATICA
nmax = 95; Rest[CoefficientList[Series[Sum[Boole[PrimePowerQ[k]] x^k/(1 + x^k), {k, 1, nmax}], {x, 0, nmax}], x]]
nmax = 95; Rest[CoefficientList[Series[Log[Product[(1 + Boole[PrimePowerQ[k]] x^k)^(1/k), {k, 1, nmax}]], {x, 0, nmax}], x] Range[0, nmax]]
Table[DivisorSum[n, (-1)^(n/# + 1) &, PrimePowerQ[#] &], {n, 95}]
PROG
(PARI) A317531(n) = sumdiv(n, d, ((-1)^(n/d+1))*(1==omega(d))); \\ Antti Karttunen, Sep 30 2018
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Jul 30 2018
STATUS
approved