(In reply to

solution by Paul)

Excellent expose, Paul.

I would like to post it as an "official" solution, - with a small modification- after the case of n=1 the sequel will be as follows:

...Let us consider n>1.

Clearly, when n is odd - x^n + 1 is even, and therefore not prime.

Now for odd values of n etc etc

I hope to get your approval of the above clarification.

Please comment