13-smaller.sagews

%time

B = 18
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-smaller.png', figsize=[8,8])

CPU time: 2821.83 s, Wall time: 3081.13 s