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A328958
a(n) = sigma_0(n) - omega(n) * nu(n), where sigma_0 = A000005, nu = A001221, omega = A001222.
12
1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, -1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, -1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, -1, 1, 0, 0, -1, 1, 2, 1, 0, 0, 0, 0, -1, 1, 0, 1, 0, 1, 0, 0
OFFSET
1,72
FORMULA
a(n) = A000005(n) - A001222(n) * A001221(n).
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
Positions of first appearances are A328962.
Zeros are A328956.
Nonzeros are A328957.
omega(n) * nu(n) is A113901(n).
(omega(n) - 1) * nu(n) is A307409(n).
sigma_0(n) - 2 - (omega(n) - 1) * nu(n) is A328959(n).
Sequence in context: A068933 A015472 A049816 * A143542 A072612 A116378
KEYWORD
sign
AUTHOR
Gus Wiseman, Nov 02 2019
STATUS
approved