OFFSET
1,2
COMMENTS
Integers in this sequence which are themselves primes include a(2) = 3, a(10) = 53, a(14) = 101, a(23) = 263, a(25) = 311, a(29) = 419, a(31) = 479, a(35) = 607, a(40) = 787. Integers in this sequence which are themselves powers greater than 1 of primes include a(7) = 27, a(11) = 64. Integers in this sequence which are perfect powers greater than 1 of composites include a(37) = 676.
FORMULA
a(n) = Sum_{i=1..n} A031218(i).
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Aug 26 2005
STATUS
approved