13.sagews

%time

B = 25
alpha = sqrt(CDF(I))
def f(z):
    return -alpha*zeta(z)
save(complex_plot(f, (-B,B),(-B,B), frame=False, axes=False, plot_points=2400), '13.png', figsize=[8,8])

CPU time: 2535.56 s, Wall time: 2777.89 s