The Vandermonde matrix with nodes $x_1 = 1, x_2 = 2, x_3 = 4$ is: $V = \begin{pmatrix} 1 & 1 & 1 \\ 1 & 2 & 4 \\ 1 & 4 & 16 \end{pmatrix}$

The determinant of a Vandermonde matrix is $\det(V) = \prod_{i < j} (x_j - x_i)$. What is $\det(V)$?