MathDB
Easy combo

Source: IOM 2017 day2 p4

September 6, 2017
combinatorics

Problem Statement

Find the largest positive integer NN for which one can choose NN distinct numbers from the set 1,2,3,...,100{1,2,3,...,100} such that neither the sum nor the product of any two different chosen numbers is divisible by 100100.
Proposed by Mikhail Evdokimov