### 2.41.7 Vandermonde matrix : `vandermonde`

`vandermonde` takes as argument a vector whose components are
denoted by *x*_{j} for *j*=0..*n*−1.

`vandermonde` returns the corresponding Vandermonde matrix
(the *k*-th row of the matrix is the vector whose components are
*x*_{i}^{k} for *i*=0..*n*−1 and *k*=0..*n*−1).

**Warning !**

The indices of the rows and columns begin at 0 with `Xcas`.

Input :

`vandermonde([a,2,3])`

Output (if `a` is symbolic else purge(a)) :

`[[1,1,1],[a,2,3],[a*a,4,9]]`