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Primes (Posted on 2003-09-09)

If x and (x² + 8) are both primes, then prove that (x³ +16) is also a prime.

See The Solution Submitted by Ravi Raja

Rating: 4.2500 (12 votes)

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Second thought

| Comment 2 of 9 |

I don't have a proof for it yet, but I think that x=3 (x²+8=17, x³+16=43) is the only number that fits these criteria at all. Can anyone find another (or a way to corroborate this)?

Posted by DJ on 2003-09-09 22:39:20

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