MathDB
Put 2n - 2 identical pebbles on the checkerboard

Source: MEMO 2008, Single, Problem 2

September 10, 2008
analytic geometrycombinatorics unsolvedcombinatorics

Problem Statement

Consider a n×n n \times n checkerboard with n>1,n∈N. n > 1, n \in \mathbb{N}. How many possibilities are there to put 2n \minus{} 2 identical pebbles on the checkerboard (each on a different field/place) such that no two pebbles are on the same checkerboard diagonal. Two pebbles are on the same checkerboard diagonal if the connection segment of the midpoints of the respective fields are parallel to one of the diagonals of the n×n n \times n square.
Back to ProblemsView on AoPS