Problem 1463. Pascal's Matrix

Given an integer n ≥ 0, generate the ( n+1) × ( n+1) lower triangular Pascal's Matrix.

Examples:

 pascalMat(0)
 ans =
     1

 pascalMat(1)
 ans =
     1     0 
     1     1 

 pascalMat(2)
 ans =
     1     0     0
     1     1     0
     1     2     1

Neither string operations nor interpolations are allowed!