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


; Print rows of the triangle from 0 to :limit inclusive.
; limit=15 gives the order 4 form per the task.
; The range of :y is arbitrary, any rows of the triangle can be printed.
 
make "limit 15
for [y 0 :limit] [
  for [x -:limit :y] [
    type ifelse (and :y+:x >= 0                ; blank left of triangle
                     (remainder :y+:x 2) = 0   ; only "even" squares
                     (bitand :y+:x :y-:x) = 0  ; Sierpinski bit test
                ) ["*] ["| |]                  ; star or space
  ]
  print []
]