MathDB
Indian Team Selection Test 2010 ST2 P2

Source:

May 22, 2010
number theoryrelatively primenumber theory unsolved

Problem Statement

Given an integer k>1k>1, show that there exist an integer an n>1n>1 and distinct positive integers a1,a2,ana_1,a_2,\cdots a_n, all greater than 11, such that the sums j=1naj\sum_{j=1}^n a_j and j=1nϕ(aj)\sum_{j=1}^n \phi (a_j) are both kk-th powers of some integers. (Here ϕ(m)\phi (m) denotes the number of positive integers less than mm and relatively prime to mm.)