M000003554

$$\pi=4\arctan\left(\frac{1}{2}\right)+8\arctan\left(\frac{1}{5}\right)-4\arctan\left(\frac{1}{12}\right)+8\arctan\left(\frac{1}{21}\right)-8\arctan\left(\frac{1}{32}\right)-8\arctan\left(\frac{1}{60}\right)+4\arctan\left(\frac{1}{99}\right)+8\arctan\left(\frac{1}{3107}\right)$$