M000000071

$$\pi=636\arctan\left(\frac{1}{239}\right)+96\arctan\left(\frac{1}{268}\right)+304\arctan\left(\frac{1}{2478}\right)-48\arctan\left(\frac{1}{247057}\right)-128\arctan\left(\frac{1}{740943}\right)+304\arctan\left(\frac{1}{620658852}\right)$$