We can write (\(a^n - 1\)), as:
$$(a-1)(a^{n-1} + a^{n-2} + \ldots + a + 1)$$
If (\(a^n - 1\)) is prime, then the first factor (\(a-1\)) has to be 1. This is only possible if \(a = 2\). Also, if \(n=1\), then the second factor would be 1.
We can write (\(a^n - 1\)), as:
If (\(a^n - 1\)) is prime, then the first factor (\(a-1\)) has to be 1. This is only possible if \(a = 2\). Also, if \(n=1\), then the second factor would be 1.