MathDB
IMC 2012 Day 1, Problem 5

Source:

July 28, 2012
algebrapolynomialnumber theoryrelatively primeIMCcollege contests

Problem Statement

Let aa be a rational number and let nn be a positive integer. Prove that the polynomial X2n(X+a)2n+1X^{2^n}(X+a)^{2^n}+1 is irreducible in the ring Q[X]\mathbb{Q}[X] of polynomials with rational coefficients.
Proposed by Vincent Jugé, École Polytechnique, Paris.