[a^1788] and [a^1988] divisible by 17
Source: IMO Shortlist 1988, Problem 7, IMO Longlist 10
October 22, 2005
algebrapolynomialmodular arithmeticnumber theoryDivisibilityIMO Shortlist
Problem Statement
Let be the greatest positive root of the equation x^3 \minus{} 3 \cdot x^2 \plus{} 1 \equal{} 0. Show that and are both divisible by 17. Here denotes the integer part of