MathDB
2015-2016 Fall OMO #8

Source:

November 18, 2015
Online Math Open

Problem Statement

The two numbers 00 and 11 are initially written in a row on a chalkboard. Every minute thereafter, Denys writes the number a+ba+b between all pairs of consecutive numbers aa, bb on the board. How many odd numbers will be on the board after 1010 such operations?
Proposed by Michael Kural