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Extra. A narrower conjecture (stronger).
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Primality of $\ \frac{b^p-a^p}{b-a}$

Can you prove the following:

Conjecture:  Let $\ p\in\mathbb P\ $ be an arbitrary prime. Then there exist two relatively prime integers $\ a\ $ and $\ b\ $ such that $\ a>0\ $ and $\ b>1\ $ and

$$ \frac{b^p-a^p}{b-a} \in\ \mathbb P. $$

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A harder question would be a restriction to $\ b=a+1.$

See also the comment below by @GHfromMO.

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