MathDB
Easy number theory: 2^b-1 divides 2^a+1

Source: Vietnam MO 1983 P1

March 18, 2011
modular arithmeticnumber theorygreatest common divisornumber theory proposed

Problem Statement

Are there positive integers a,ba, b with b2b \ge 2 such that 2a+12^a + 1 is divisible by 2b12^b - 1?