M000000073

$$\pi=508\arctan\left(\frac{1}{239}\right)+512\arctan\left(\frac{1}{515}\right)+240\arctan\left(\frac{1}{11432}\right)+112\arctan\left(\frac{2}{81487}\right)-336\arctan\left(\frac{1}{173932}\right)+240\arctan\left(\frac{1}{2456007}\right)$$