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Old 2021-08-26, 15:54   #12
Dr Sardonicus
 
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Feb 2017
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Quote:
Originally Posted by bur View Post
Let p and p^2+8 be prime. Prove that p^3+4 is also prime.

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So only if p=3 we can have both p and p^2+8 be prime.
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Or is it really just about showing that it only holds for p=3 and since 3^3+4=31 is prime, that's the proof?
Yup.

Last fiddled with by Dr Sardonicus on 2021-08-26 at 15:56
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