Hans Havermann <hahaj at rogers.com> wrote: > > These are the values of n such that 2^n+5 is prime (up to 3000): > > 1, 3, 5, 11, 47, 53, 141, 143, 191, 273, 341 > > I believe the next n is 16541. > How are 1 and 3 primes of the form 2^n+5? Is 1 + (pi/ln(2))i one of the allowed values of n?