MathDB

C1

Part of 2015 Indonesia MO Shortlist

Problems(1)

2015 elephants on a chessboard of dimensions 2x 2015 without threats

Source: INAMO Shortlist 2015 C1

5/14/2019
Given natural number n. Suppose that NN is the maximum number of elephants that can be placed on a chessboard measuring 2×n2 \times n so that no two elephants are mutually under attack. Determine the number of ways to put NN elephants on a chessboard sized 2×n2 \times n so that no two elephants attack each other.
Alternative Formulation: Determine the number of ways to put 20152015 elephants on a chessboard measuring 2×20152 \times 2015 so there are no two elephants attacking each othe
PS. Elephant = Bishop
combinatoricsChessboardchess