MathDB
2016 LMT Theme #14

Source:

April 11, 2016

Problem Statement

A ladder style tournament is held with 20162016 participants. The players begin seeded 1,2,20161,2,\cdots 2016. Each round, the lowest remaining seeded player plays the second lowest remaining seeded player, and the loser of the game gets eliminated from the tournament. After 20152015 rounds, one player remains who wins the tournament. If each player has probability of 12\tfrac{1}{2} to win any game, then the probability that the winner of the tournament began with an even seed can be expressed has pq\tfrac{p}{q} for coprime positive integers pp and qq. Find the remainder when pp is divided by 10001000.
Proposed by Nathan Ramesh