OFFSET
1,2
COMMENTS
Only five in the first 200 indices give odd values: 25, 36, 49, 100, 169.
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5000
EXAMPLE
For n=12, the number of divisors is 6 (1, 2, 3, 4, 6, and 12), and the number of primes <= n is 5 (2, 3, 5, 7, and 11). So a(12) = 6 * 5 = 30. - Michael B. Porter, Jun 08 2018
MATHEMATICA
Table[DivisorSigma[0, n]*PrimePi[n], {n, 1, 100}]
PROG
(PARI) for(n=1, 100, print1(numdiv(n)*primepi(n), ", ")) \\ G. C. Greubel, Jun 05 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Roger L. Bagula, Sep 07 2008
EXTENSIONS
Edited by the Associate Editors of the OEIS, Jun 08 2018
STATUS
approved