MathDB
A 19

Source:

May 25, 2007
inductionmodular arithmeticLaTeXDivisibility Theorynumber theory

Problem Statement

Let f(x)=x3+17f(x)=x^3 +17. Prove that for each natural number n2n \ge 2, there is a natural number xx for which f(x)f(x) is divisible by 3n3^n but not 3n+13^{n+1}.