Where can one find chaotic toy algorithms that don't involve Turing machines or cellular automata? (I need one for a project, and I keep running into image processing and biology applications. I actually need a toy one.)

EDIT: Found it: (pseudocode, not Python)

    while x > 1
         case ((x mod 2) == 0):
             x = x / 2
         case ((x mod 3) == 0):
             x = x + 1
         default:
             x = x * 3

The number of iterations it takes to leave the loop is chaotic.