MathDB

1

Part of 2020 Iranian Our MO

Problems(1)

Tetromino

Source: Iranian Our MO 2020 P1

3/11/2020
Find the maximum number of cells that can be coloured from a 4×30004\times 3000 board such that no tetromino is formed.
Proposed by Arian Zamani, Matin Yousefi Rated 5
combinatorics