@Peter can you find a semi prime of the form $n^n+n!$ with $n \gt 7$?

For such a semiprime, $n$ and $n^{n-1}+(n-1)!$ both must be prime. I am searching for an example.

@Mathphile No semiprime for $7\lt n \lt 4\ 300$

@Mathphile No semiprime for $7\lt n\lt 8 200$

@pantareis I would have two projects for mathphile's conjectures : (1) Factor 2^3315+3315 $(2)$ Search a prime of the form n^(n-1) + (n-1)! for n prime (which gives semiprime n^n+n!)

seems like Enzo Creti is very busy these days

yes, seems so

I passed 8 600 , no further example.

okay

i'll search for semi primes of the form $n^n-n!$, $n \gt 7$

@Mathphile Where did you arrive ?

@Peter program hasn't ended

Ah, you chose $n^n-n!$, but I think $n$ must be prime in this case as well.

Why don't you use yafu for the search ?

Just create a textfile with these lines :

@Peter i haven't downloaded yafu

can pfgw be used?

sorry, I mean pfgw

-f100 ?

@Peter?

yes

I cannot go to factordb at the moment - strange.

@Mathphile