1

First prime is $p_1=7$ is for $n=2$.

Checking $n=\{3,...,10\}$ gives no primes.

How to evaluate primality in this case ($n^3-1$) and in general case (mathematical solution)?

user300045
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1 Answers1

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Hint: Note that $$ n^3 - 1 = (n-1)(n^2 + n + 1) $$ When can this be a prime?

Arthur
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