Mandel/Julia hybrids, Part 1

Mandelbrot/Julia hybrids

Consider the Mandelbrot and Julia formulas:
z_n+1=z_n² + c_m
z_n+1=z_n² + c_j
Where c_m is changed for each pixel when calculating the Mandelbrot image and c_j is constant for each pixel when calculating Julia images.
The hybrids below uses different methods to mix the two c's together in one picture.

Part 1
Alternates between using c_m and c_j using different patterns for each iteration.

Part 2
c = (1 - k) * c_m + k * c_j, With k = 0 at iteration 1 and k = 1 at maximum iteration.

Part 3
c = (1 - k) * c_m + k * c_j, With k = 0.5 * sin(period * iteration) + 0.5.
Several different periods were used.

Part 4
c = 0.5 * c_m + 0.5 * c_j