M000000963

$$\pi=16\arctan\left(\frac{1}{4}\right)-16\arctan\left(\frac{1}{27}\right)-16\arctan\left(\frac{1}{86}\right)-8\arctan\left(\frac{1}{478}\right)+16\arctan\left(\frac{1}{939}\right)-16\arctan\left(\frac{1}{1764383}\right)+4\arctan\left(\frac{1}{54608393}\right)$$