I saw this gorgeous Paul Noble pencil sketch called Sea 7B: http://mathhombre.tumblr.com/post/149700428209/nearlya-paul-noble-sea-7b-2007-pencil-on
I'm always looking for weird function/pattern representation, so built this sketch to be able to show many different circle patterns. N controls how many rows, dlt (delta) is the spacing between, and the # per line is the function that tells you how many per row, starting with row 1 and going up. If you want to change the maximum number of rows, enter a new value for Nmax.