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A Woodall number is an integer of the form $n 2^{n}-1$.

A Woodall prime is an integer that is both a prime and a Woodall number.

Let $p$ be a prime of the form 1 mod 4.

Then $p 2^{p} -1$ is never a ( Woodall ) prime.

How to prove this ?

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    $n$ such that $n2^n-1$ is prime are tabulated at https://oeis.org/A0022342017-07-20

0 Answers 0