MathDB
compare no of ways for 2 paths along surface of cube

Source: Switzerland - 2012 Swiss MO Final Round p8

January 14, 2023
combinatoricscombinatorial geometrygeometry3D geometry

Problem Statement

Consider a cube and two of its vertices AA and BB, which are the endpoints of a face diagonal. A path is a sequence of cube angles, each step of one angle along a cube edge is walked to one of the three adjacent angles. Let aa be the number of paths of length 20122012 that starts at point AA and ends at AA and let b be the number of ways of length 20122012 that starts in AA and ends in BB. Decide which of the two numbers aa and bb is the larger.