1. The problem statement, all variables and given/known data if 1 + 2^n + 4^n is a prime number then n is a power of 3 2. Relevant equations 3. The attempt at a solution If n is not a power of 3, i need to show that we can factorize 1 + 2^n + 4^n But im not really sure what should n be if it is not a power of 3 ? is it 3^k*m where m ≥ 1, k≥0 this direction doesnt seem to work there must be some trick here.