mandelbrot := proc(x, y) 
local c, z, m; 
c := evalf(x+y*I); z := c; 
for m to 50 while abs(z) < 2 do z := z^2+c od; 
m end;

plots[densityplot](mandelbrot,-2 .. 0.7, -1.35 .. 1.35,
s_tyle=patchnogrid,colorstyle=HUE,numpoints=62500,axes=none);