MathDB
Yet another array!

Source: INMO 1997 Problem 5

October 6, 2005
combinatorics unsolvedcombinatorics

Problem Statement

Find the number of 4×44 \times 4 array whose entries are from the set {0,1,2,3}\{ 0 , 1, 2, 3 \} and which are such that the sum of the numbers in each of the four rows and in each of the four columns is divisible by 44.