Erdős Problem #1065

Are there infinitely many primes $p$ such that $p=2^kq+1$ for some prime $q$ and $k\geq 0$? Or $p=2^k3^lq+1$?

number theory

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This is mentioned in problem B46 of Guy's collection [Gu04].

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This page was last edited 30 September 2025.

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Formalised statement? Yes
Related OEIS sequences: A074781 A339465

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