OFFSET
1,4
COMMENTS
1 is considered here to be a power of a prime. 0 is not considered here to be a power of a prime.
LINKS
Diana Mecum, Table of n, a(n) for n = 1..1049
EXAMPLE
The divisors of 9 are 1,3,9. 1 is one more than 0, not a power of a prime. 3 is one more than 2, a power of a prime. And 9 is one more than 8, a power of a prime. There are therefore 2 such divisors that are each one more than a power of a prime. So a(9)=2.
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Jun 12 2008
EXTENSIONS
Corrected and extended by Diana L. Mecum, Jul 05 2007
STATUS
approved