OFFSET
1,2
LINKS
Carl R. White, Table of n, a(n) for n = 1..10000
EXAMPLE
k=11: 2*prime(11) - 1 = 2*31 - 1 = 61 is prime, so k=11 belongs to the sequence.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Ctibor O. Zizka, Apr 05 2008
EXTENSIONS
More terms from Paolo P. Lava, Apr 15 2008
STATUS
approved