Hilbert matrix.

  HILB(N) is the N by N matrix with elements 1/(i+j-1),

  which is a famous example of a badly conditioned matrix.

  See INVHILBCDXX3WM for the exact inverse.



  This is also a good example of efficient MATLAB programming

  style where conventional FOR227HPXR or DO loops are replaced by

  vectorized statements.  This approach is faster, but uses

  more storage.