OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
The values of mu of the balanced numbers 3, 6 and 12 are -1, 1 and 0 respectively.
MATHEMATICA
MoebiusMu /@ Select[Range[10^5], Divisible[DivisorSigma[1, #], EulerPhi[#]] &] (* Amiram Eldar, Dec 05 2019 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Labos Elemer, Dec 06 2002
STATUS
approved