Primes of form Power of Two plus One/Proof 2
Jump to navigation
Jump to search
Theorem
Let $n \in \N$ be a natural number.
Let $2^n + 1$ be prime.
Then $n = 2^k$ for some natural number $k$.
Proof
A specific instance of Primes of form Power plus One:
$q^n + 1$ is prime only if:
- $(1): \quad q$ is even
and
- $(2): \quad n$ is of the form $2^k$ for some positive integer $k$.
As $2$ is even, the result applies.
$\blacksquare$