Prime factors of $\sum_{k=1}^{30}k^{k^k}$
I wrote a small C program using the n_powmod2_preinv function in the Flint Number Theory Library. I used the tricks you already mentioned and checked up to $5\cdot10^{10}$ and didn't find any factors.
Prime factors of $\sum_{k=1}^{30}k^{k^k}$
I wrote a small C program using the n_powmod2_preinv function in the Flint Number Theory Library. I used the tricks you already mentioned and checked up to $5\cdot10^{10}$ and didn't find any factors.