Click on the green flag and then press space for the next iteration.
I know of four other ways, using different methods, to compute the Sierpinski triangle. My Sierpinski Triangle projects can be seen at: (1) Barnsley's Chaos Game - Midpoint Formula http://scratch.mit.edu/projects/13649502/ (2) Barnsley's Collage Theorem http://scratch.mit.edu/projects/3116188/ (3) Wolfram’s Rule 90 Linear Cellular Automaton http://scratch.mit.edu/projects/11024434/ (4) Nested Triangles http://scratch.mit.edu/projects/11181928/
