3 Matrix Determinants and a Puzzle

In this video, I present three different ways of calculating the determinant of a matrix

00:00 Introduction
03:23 Row reduction
10:50 Sum of Products
21:37 Expansion
29:43 The puzzle
What are the possible determinants of an n x n matrix, all of whose entries are 0s and 1s, with at most two 1s in each row and each column?