MathDB
2^k+1 integers, select k+2 with given property

Source: Kürschák 1999, problem 3

July 15, 2014
combinatorics unsolvedcombinatorics

Problem Statement

We are given more than 2k2^k integers, where kNk\in\mathbb{N}. Prove that we can choose k+2k+2 of them such that if some of our selected numbers satisfy x1+x2++xm=y1+y2++ymx_1+x_2+\dots+x_m=y_1+y_2+\dots+y_m where x1<<xmx_1<\dots<x_m and y1<<ymy_1<\dots<y_m, then xi=yix_i=y_i for any 1im1\le i\le m.