Question: Determinant of Vandermonde Matrix

Calculate the determinant of the square Vandermonde matrix     (A is alpha)

     1   Α₁    A₁²   A₁³       

     1   A₂    A₂²   A₂³ 

V= 1   A₃    A₃²   A₃³  

     1   A₄    A₄²   A₄³

The derterminant of an nxn Vandermonde matrix can be expressed as

det(V)=  ∏      (A_j-A_i)

          1≤i<j≤n

Write a procedure pdetVandermonde which takes a list A=[A₁,A2,A₃,...A_n] and calculates

its determinant using the formula above.  This can be done using a double loop (note i<j).

I'm not sure exactly what to do for this, I tried to just get the Vandermonde matrix but I did it like

this.

>V:=Vector[row]([A₁,A₂,A₃,A₄]);

>LinearAlgebra[VandermondeMatrix](V);

This got me the matrix in the beginning of the question.  I tried using the formula given but the 1≤i<j≤n

would not work with it in maple.