L-tetromino, infinite grid
Source: Switzerland - 2007 Swiss MO Final Round p3
December 26, 2022
combinatoricsTilingtiles
Problem Statement
The plane is divided into unit squares. Each box should be be colored in one of colors , so that if four squares can be covered with an -tetromino, then these squares have four different colors (the -Tetromino may be rotated and be mirrored). Find the smallest value of for which this is possible.