MathDB
how many ways are there to move n times following the arrows

Source: KJMO 2014 p3

May 2, 2019
combinatorics

Problem Statement

Find the number of nn-movement on the following graph, starting from SS. https://cdn.artofproblemsolving.com/attachments/2/0/4a23c83c7f5405575acbe6d09f202d87341337.png