Number Theory with game
Source: Balkan MO Shortlist 2020 N2
September 14, 2021
number theory
Problem Statement
A number of children are at a party and they sit in a circle to play a game of Pass and Parcel. Because the host has no other form of entertainment, the parcel has infinitely many layers. On turn , starting with , the following two things happen in order:
The parcel is passed positions clockwise; and
The child currently holding the parcel unwraps a layer and claims the prize inside.
For what values of will every chidren receive a prize?