OFFSET
1,3
COMMENTS
EXAMPLE
The divisors of 6 are 1, 2, 3, 6. But 1 and 2 are powers of 2, so we only add up 3, 6 to get 9, and add that to the running total of 8 to get a(6) = 17.
MATHEMATICA
Accumulate[Table[DivisorSigma[1, n] - Denominator[DivisorSigma[1, 2n]/DivisorSigma[1, n]], {n, 100}]] (* Alonso del Arte, Nov 18 2019, based on Wesley Ivan Hurt's program for A326988 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Sep 14 2019
STATUS
approved