This is the recurrence formula

Cool fractals

Mandelbrot C + Zn^2
BurningShip C + |Zn|^2

What's this ?

Each point you see has a coordinate in the complexe plane. On each of them, repeat the following operation:

Z n+1 = formula(Zn)

If the value becomes too large, or the operation has been repeated enough, stop and assign a color based on the number of times the operation was repeated.