4x4 table and 16 squares
Source: JBMO 2008 Problem 4
June 25, 2008
linear algebramatrixvectorcombinatorics proposedcombinatorics
Problem Statement
A table is divided into white unit square cells. Two cells are called neighbors if they share a common side. A move consists in choosing a cell and the colors of neighbors from white to black or from black to white. After exactly moves all the cells were black. Find all possible values of .