OFFSET
1,1
REFERENCES
J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 64, p. 23, Ellipses, Paris 2008.
EXAMPLE
a(3) = 64, as 64 has 1, 65 has 2 and 66 has 3 prime divisors: 64 = 2^6, 65 = 5*13 and 66 = 2*3*11.
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Amarnath Murthy, Aug 30 2003
EXTENSIONS
More terms from Don Reble, Sep 13 2003
a(7) from Donovan Johnson, Mar 06 2008
a(8) from Donovan Johnson, Jul 19 2011
STATUS
approved