About the Cover

About the CoverThe cover image is from the Proof Without Words "Game of Parts," by Richard Ehrenborg.In the game, you start with one pile of n chips and, at each move, take a pile of k chips and divide it into two piles containing i chips and ki chips, respectively, receiving i (ki) points.The goal is to end with n piles, each having one chip.The figure illustrates that the total number of points you receive at the end of the game is the (n -1)st triangular number.