olymmath

IMO 2023 Problem 4

  • Day 2

Let x1,x2,…,x2023x_1,x_2,\dots,x_{2023} be pairwise different positive real numbers such that an=(x1+x2+⋯+xn)(1x1+1x2+⋯+1xn)a_n=\sqrt{(x_1+x_2+\dots+x_n)\left(\frac{1}{x_1}+\frac{1}{x_2}+\dots+\frac{1}{x_n}\right)} is an integer for every n=1,2,…,2023.n=1,2,\dots,2023. Prove that a2023⩾3034.a_{2023} \geqslant 3034.

Official text Transcription from AI-MO AoPS, checked word for word against the official paper. Quoted with source.

Official text: IMO 2023 official English paper, page 2.

Solutions

No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.

Add a solution

Locator imo/2023/p4 · Tag FG8PQHDEY7 · Edit this page on GitHub · Keys: j next, k previous