This is a repost from Mathematics Stack Exchange due to lack of answers.
A minor is a determinant of a square matrix formed from a bigger square matrix by removing rows and columns. A minor having value zero means that its associated submatrix is non invertible.
The amount of zero valued minors of a size n discrete Fourier transform matrix seems to depend on the amount of divisors of n where more zero valued minors are found with more divisors.
How can it be shown?
How can the amount of zero valued minors be determined?