MathDB
r_k is largest quantity of different elements of A so that they differ not k

Source: Cono Sur 2002 P5

August 1, 2018
combinatoricsnumber theorymaximumDifferencecono sur

Problem Statement

Consider the set A={1,2,...,n}A = \{1, 2, ..., n\}. For each integer kk, let rkr_k be the largest quantity of different elements of AA that we can choose so that the difference between two numbers chosen is always different from kk. Determine the highest value possible of rkr_k, where 1kn21 \le k \le \frac{n}{2}