If x and (x² + 8) are both primes, then prove that (x³ +16) is also a prime.
(In reply to
re: Second thought by SilverKnight)
More to the point... I think that if x is prime, x²+8 can not be prime for any x other than 3.
Therefore, the formula x³+16 is a red herring.... and the statement would be JUST as true if I wrote the third part as x³+14 or x³+2 or x²+2 (or any other formula based on x=3 that results in a prime number).
My head hurts.... anyone wanna corroborate this?