OFFSET
1,1
EXAMPLE
4 is a term: 4 = 2*2 has 2 prime factors (counted with multiplicity) and 3 divisors (1, 2, and 4), and 2 + 3 = 5 (a prime).
8 is a term: 8 = 2*2*2 has 3 prime factors and 4 divisors (1, 2, 4, and 8), and 3 + 4 = 7 (a prime).
9 is a term: 9 = 3*3 has 2 prime factors and 3 divisors (1, 3, and 9), and 2 + 3 = 5 (a prime).
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Mar 16 2009, Nov 14 2009
EXTENSIONS
Corrected (148 replaced with 138) by R. J. Mathar, May 19 2010
STATUS
approved