$ \forall n > 0, n \in \mathbb{Z},$ there exists uniquely determined integers $ a_n, b_n, c_n \in \mathbb{Z}$ such \[ \left(1 + 4 \cdot \sqrt[3]{2} - 4 \cdot \sqrt[3]{4} \right)^n = a_n + b_n \cdot \sqrt[3]{2} + c_n \cdot \sqrt[3]{4}.\] Prove that $ c_n = 0$ implies $ n = 0.$
Problem
Source: IMO Shortlist 1989, Problem 9, ILL 22
Tags: algebra, irrational number, number theory, IMO Shortlist, equation