RosettaCodeData/Task/Sierpinski-triangle-Graphical/Racket/sierpinski-triangle-graphical-1.rkt

#lang racket
(require 2htdp/image)
(define (sierpinski n)
  (if (zero? n)
    (triangle 2 'solid 'red)
    (let ([t (sierpinski (- n 1))])
      (freeze (above t (beside t t))))))