MathDB

each unit square has two red and two blue vertices in nxn grid

Source: Mathematics Regional Olympiad of Mexico Center Zone 2008 P3

November 9, 2021

Coloringcombinatorics

Problem Statement

Consider a

n \times n

grid divided into

n ^ 2

squares of

1 \times 1

. Each of the

(n + 1) ^ 2

vertices of the grid is colored red or blue. Find the number of coloring such that each unit square has two red and two blue vertices.