http://i.stack.imgur.com/bGpfy.png http://i.stack.imgur.com/bGpfy.png You're right, thanks. So if the inner space is shaded, it produces the "Sierpinski pentago

http://i.stack.imgur.com/bGpfy.png http://i.stack.imgur.com/bGpfy.png You're right, thanks. So if the inner space is shaded, it produces the "Sierpinski pentagon", and this can be iterated indefinitely.