📖 Fermat Prime
A Fermat prime is a prime of the form $F_k = 2^{2^k} + 1$. The known Fermat primes are $F_0 = 3$, $F_1 = 5$, $F_2 = 17$, $F_3 = 257$, $F_4 = 65537$.
From: Disquisitiones Arithmeticae
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