MathDB
An function form N to N

Source: EMC 2014 P4

December 14, 2014
functioninductionnumber theory proposednumber theory

Problem Statement

Find all functions ff from positive integers to themselves such that: 1)f(mn)=f(m)f(n)f(mn)=f(m)f(n) for all positive integers m,nm, n 2){1,2,...,n}={f(1),f(2),...f(n)}\{1, 2, ..., n\}=\{f(1), f(2), ... f(n)\} is true for infinitely many positive integers nn.
Back to ProblemsView on AoPS