By Catalan’s conjecture, 2−1−pk = 1 has no solution only when −1 > 1 and k > 1. Thus it suffices to consider only the case when − 1 ≤ 1 or k ≤ 1. We know that > 1, +1 = qy, q is prime, and k ≥ 1. This implies that q = 3 and y = 1 ; or k = 1.
By Catalan’s conjecture, 2 −1−pk = 1 has no solution only when −1 > 1and k > 1. Thus it suffices to consider only the case when − 1 ≤ 1 or k ≤ 1.We know that > 1, +1 = qy, q is prime, and k ≥ 1. This implies that q = 3and y = 1 ; or k = 1.