MathDB
Initial conditions for a solitaire-type game

Source: Baltic Way 2017, Problem 6

November 26, 2017
combinatoricscombinatorics proposed

Problem Statement

Fifteen stones are placed on a 4×44 \times 4 board, one in each cell, the remaining cell being empty. Whenever two stones are on neighbouring cells (having a common side), one may jump over the other to the opposite neighbouring cell, provided this cell is empty. The stone jumped over is removed from the board.
For which initial positions of the empty cell is it possible to end up with exactly one stone on the board?