this is a nice starter if you want to calculate stuff. Function for prime counting
https://s0.wp.com/latex.php?latex=%5Cdisplaystyle%5Cpi%28x%29+%3D+%5Csum_%7Bn+%3D+1%7D%5E%5Cinfty+%5Cfrac%7B%5Cmu%28n%29%7D%7Bn%7D+J%28%5Csqrt%5Bn%5D%7Bx%7D%29+&bg=ffffff&fg=2b2b2b&s=2