no of tidy 3n-tables
Source: Norwegian Mathematical Olympiad 2021 - Abel Competition p1a
May 29, 2021
combinatoricsnumbers in a tabletable
Problem Statement
A -table is a table with three rows and columns containing all the numbers . Such a table is called tidy if the numbers in the first row appear in ascending order from left to right, and the three numbers in each column appear in ascending order from top to bottom. How many tidy -tables exist?