I understand that this is true.
Primes are always odd so a would naturally have to be even, if $1$ is being added to it.
For example, $4^2+1 = 17$.
But I'm not quite sure how to prove this.
I understand that this is true.
Primes are always odd so a would naturally have to be even, if $1$ is being added to it.
For example, $4^2+1 = 17$.
But I'm not quite sure how to prove this.