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


  [ [ dup 1 &
      iff char * else space
      emit
      1 >> dup while
      sp again ]
    drop ]                    is stars    (  mask --> )
 
  [ bit
    1 over times
      [ cr over i^ - times sp
        dup stars
        dup 1 << ^ ]
    2drop ]                   is triangle ( order --> )
 
  4 triangle