Thanks, CRGreathouse for those terms. To make sure (so an OEIS sequence can be added), are these the correct indices n (for a(n)) in order up to n = 20k?
I will try to add in an OEIS sequence if so.
Also just for curiosity, what is the density for the prime indices n such that a(n) is prime for compared to the primes n such that 2^n1 (Mersenne) is prime for?
In other words, for any prime n, what is the (approximate) probability that a(n) is prime for, and for any given prime n, is there a greater chance that a(n) or 2^n1 is prime for?
Last fiddled with by carpetpool on 20170316 at 23:56
