erase 2 numbers with prime sum 1-510 May Olympiad (Olimpiada de Mayo) 2015 L2 P4
Source:
September 26, 2021
combinatoricsprimenumber theory
Problem Statement
The first positive integers are written on a blackboard: . An operation consists of of erasing two numbers whose sum is a prime number. What is the maximum number of operations in a row what can be done? Show how it is accomplished and explain why it can be done in no more operations.