OFFSET
1,1
EXAMPLE
n = 5: a(5) = 52, sigma_2(52) = 2704+676+169+16+4+1 = 3570 = 2*3*5*7*17.
PROG
(PARI) { for (n=1, 100, m=1; while(omega(sigma(m, 2)) != n, m++); write("b066089.txt", n, " ", m) ) } \\ Harry J. Smith, Nov 12 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Dec 04 2001
EXTENSIONS
Terms a(11) - a(13) from Harry J. Smith, Nov 12 2009
a(14)-a(15) from Donovan Johnson, Apr 16 2013
STATUS
approved