OFFSET
1
COMMENTS
If p is prime, a(p) = mu(d(p)) = mu(2) = -1.
EXAMPLE
a(6) = mu(d(6)) = mu(4) = 0.
MATHEMATICA
Table[MoebiusMu[DivisorSigma[0, n]], {n, 100}]
CROSSREFS
KEYWORD
sign
AUTHOR
Wesley Ivan Hurt, May 31 2021
STATUS
approved