OFFSET
1,2
EXAMPLE
5 is in the sequence, since prime(5)=11 and (2*11-1)^(2*11-1) mod 2^(2*11-1) = 21^21 mod 2^21 = 1472837 is prime.
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Jan 01 2011
STATUS
approved