D.2 Python Output:

0.12548190236470805
0.1254917624198063 0.6768927381439971 0.5345668734285826
0.999921428666646 0.1853793005798416 0.2347356497418134

Here, we see that the density of the intersection integer circles centred at $(0,0),(1,0)$ and $(0,1)$ is very close to $\prod\limits_{p\in{\mathbb{P}}}\left(1-\frac{3}{p^{2}}\right)$.