OFFSET
1,1
COMMENTS
The two primes generated from p and q are sometimes called flip-flap twin primes. There is probably an infinity of them.
EXAMPLE
a(2) = 14 since (2*7)^2 + 2^2 - 7^2 = 151 and (2*7)^2 - 2^2 + 7^2 = 241 are both primes.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Olivier Gérard, Feb 19 2003
STATUS
approved