Balanced table containing the numbers 1,2,...,n^2
Source: Moldova IMO-BMO TST 2003, day 3, problem 4
August 16, 2008
Problem Statement
A square-table of dimensions , where , is filled arbitrarly with the numbers such that every number appears on the table exactly one time. From each row of the table
is chosen the least number and then denote by the biggest number from the numbers chosen. From each column of the table is chosen the least number and then denote by the biggest number from the numbers chosen. The table is called balanced iff x \equal{} y. How many balanced tables we can obtain?