MathDB
Putnam 2016 B4

Source:

December 4, 2016
PutnamPutnam 2016Putnam matrices

Problem Statement

Let AA be a 2n×2n2n\times 2n matrix, with entries chosen independently at random. Every entry is chosen to be 00 or 1,1, each with probability 1/2.1/2. Find the expected value of det(AAt)\det(A-A^t) (as a function of nn), where AtA^t is the transpose of A.A.