OFFSET
1,72
EXAMPLE
a(144) = sigma_0(144) - omega(144) * nu(144) = 15 - 6 * 2 = 3.
MATHEMATICA
Table[DivisorSigma[0, n]-PrimeOmega[n]*PrimeNu[n], {n, 100}]
CROSSREFS
KEYWORD
sign
AUTHOR
Gus Wiseman, Nov 02 2019
STATUS
approved