Problem

Source: Hungary-Israel Binational Olympiad 2009, Problem 3

Tags: function, induction, inequalities, algebra unsolved, algebra



Does there exist a pair $ (f; g)$ of strictly monotonic functions, both from $ \mathbb{N}$ to $ \mathbb{N}$, such that \[ f(g(g(n))) < g(f(n))\] for every $ n \in\mathbb{N}$?