M000000970

$$\pi=16\arctan\left(\frac{1}{4}\right)-16\arctan\left(\frac{1}{27}\right)-4\arctan\left(\frac{1}{41}\right)-16\arctan\left(\frac{1}{86}\right)+8\arctan\left(\frac{1}{99}\right)+16\arctan\left(\frac{1}{939}\right)-16\arctan\left(\frac{1}{1764383}\right)$$