OFFSET
1,1
EXAMPLE
prime(2^2)+prime(2^1) + 1 = 11 = prime.
PROG
(PARI) f(n)= for(x=1, n, y=prime(2^x)+ prime(2^(x-1))+1; if(isprime(y), print1(y", ")))
CROSSREFS
KEYWORD
hard,nonn
AUTHOR
Cino Hilliard, Feb 20 2004
STATUS
approved