Task
Produce an ASCII representation of a Sierpinski triangle of order   N.



Example
The Sierpinski triangle of order   4   should look like this:

                       *
                      * *
                     *   *
                    * * * *
                   *       *
                  * *     * *
                 *   *   *   *
                * * * * * * * *
               *               *
              * *             * *
             *   *           *   *
            * * * *         * * * *
           *       *       *       *
          * *     * *     * *     * *
         *   *   *   *   *   *   *   *
        * * * * * * * * * * * * * * * *



Related tasks
 Sierpinski triangle/Graphical for graphics images of this pattern. 
 Sierpinski carpet


def sierpinski
    2 swap power 1 - var lim    
    lim 0 -1 3 tolist for
        var y        
        32 y 1 + repeat print
        0 lim y - 2 tolist for
            y bitand if 32 32 chain else "* " endif print
        endfor
        nl
    endfor
enddef
 
5 for
    sierpinski
endfor