M000000636

$$\pi=-122\arctan\left(\frac{1}{2}\right)+244\arctan\left(\frac{1}{4}\right)-34\arctan\left(\frac{1}{463}\right)+6\arctan\left(\frac{1}{1164}\right)+34\arctan\left(\frac{1}{390112}\right)-6\arctan\left(\frac{1}{9485443}\right)$$