Quote:
Originally Posted by Dylan14
Doing a quick search with pfgw with the f1 flag, the following numbers are prime or 3PRP for the form x!^2 +/ 1 up to x = 2000:
Code:
0!^2+1
1!^2+1
2!^2+1
3!^2+1
4!^2+1
5!^2+1
9!^2+1
10!^2+1
11!^2+1
13!^2+1
24!^2+1
65!^2+1
76!^2+1
2!^21

I wouldn't expect anything else on the 1 side as x^n1 always factors as (x1) as a factor. Note that on the +1 side any primes must also be GFNs which means that n will always be a power of 2 for primes.
So from those perspectives, these forms are not that interesting.