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


program Sierpinski;
 
function ipow(b, n	: Integer) : Integer;
var
   i : Integer;
begin 
   ipow := 1;
   for i := 1 to n do
      ipow := ipow * b
end;
 
function truth(a : Char) : Boolean;
begin
   if a = '*' then
      truth := true
   else
      truth := false
end;