Technical data for this type of fractal : click here.
For the fractal here :
fn1=sin, fn2=sin, fn3=sin, fn4=tan
real(p1) = -6, imag(p1) = 128, real(p2) = 0.15, imag(p2) = 0, real(p3) = -0.5, imag(p3) = -0.2
Note : many values of the above parameters conduct to very complex images.