MathDB
largest no of moves the fairy chess piece leopard could have made

Source: 2019 RMM Shortlist C2

June 19, 2020
combinatorics

Problem Statement

Fix an integer n2n \ge 2. A fairy chess piece leopard may move one cell up, or one cell to the right, or one cell diagonally down-left. A leopard is placed onto some cell of a 3n×3n3n \times 3n chequer board. The leopard makes several moves, never visiting a cell twice, and comes back to the starting cell. Determine the largest possible number of moves the leopard could have made.
Dmitry Khramtsov, Russia