last numbers on board from 1-2013
Source: 2013 Argentina OMA Finals L3 p5
January 15, 2023
combinatoricsalgebra
Problem Statement
Given several nonnegative integers (repetitions allowed), the allowed operation is to choose a positive integer and replace each number greater than or equal to by (the numbers , if any, are replaced by ). Initially, the integers from are written on the blackboard until inclusive. After a few operations the numbers on the board have a sum equal to . Determine what the numbers that remained on the board could be. Find all the possibilities.