OFFSET
1,3
LINKS
Harry J. Smith, Table of n, a(n) for n=1..1000
EXAMPLE
sigma_2(12) = 144 + 36 + 16 + 9 + 4 + 1 = 210, so a(12)=4.
MATHEMATICA
PrimeNu[DivisorSigma[2, Range[110]]] (* Harvey P. Dale, Feb 23 2015 *)
PROG
(PARI) { for (n=1, 1000, a=omega(sigma(n, 2)); write("b066088.txt", n, " ", a) ) } \\ Harry J. Smith, Nov 11 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Dec 04 2001
EXTENSIONS
OFFSET changed from 0 to 1 by Harry J. Smith, Nov 11 2009
STATUS
approved