Problems & Puzzles:
Problems
Problem 52.
±p ± 2^n
F. Cohen and J. L. Selfridge observed in 1975 that
47867742232066880047611079
is a
prime number
such that plus or minus a power of 2 can never be
prime.
Q1. Can you find a smaller solution?
Q2. Just take p+2^n and get champions
of this type

|