For d odd, is there a prime of the form 2ⁿ + d? — The Ross Program
Channel: Jim Fowler
Date: 2020-07-27

Inspired by Fermat primes, 2¹ + 1, 2² + 1, 2⁴ + 1, 2⁸ + 1, 2¹⁶ + 1, we seek primes of the form 2ⁿ + d.  We specifically find an n so that 2ⁿ + 61 is prime, and consider the surprising case of 2ⁿ + 1518781.

Credit goes to https://math.dartmouth.edu/~carlp/PDF/covertalkunder.pdf for introducing this neat result to me; this video fixes an arithmetic error in those notes.