Here :
Prime candidates of the form $n^{(n^n)}+n^n+1$?
I asked for the prime factors of $f(12)$ and $f(60)$, where $$f(n)=n^{(n^n)}+n^n+1$$
I would like to accelarate the search of the prime factors of $f(n)$.
Are there special properties considerably restricting the possible prime factors of $f(n)$ ?
The only numbers I factored completely so far, are $f(1),f(2),f(3)$ and $f(4)$. For those, who are interested, here are the factoriations :
Small prime factors of the expression (to 100k), for use in testing any hypothesis.
Observations: Multiples of $6$ have some kind of restricted options going on. Numbers $\{1,2,4\}\bmod 6$ have the expression divisible by $3$, others not. If $n{+}2$ is an odd prime or prime power, that prime divides the expression. If $2n{-}1$ is prime, that is often a factor.