Dev talk:2.4/Doc/How to/Add a Procedural Texture
Since the math module hasn't been installed yet, I've written a version of the julia formula in wiki syntax. If you want to use it, the code is
z''<sub>n+1<sup>2</sup></sub>'' = z<sub>n</sub> - c
It renders as zn+12 = zn - c.
-- Joeedh