M000000960

$$\pi=10\arctan\left(\frac{1}{3}\right)-2\arctan\left(\frac{1}{4}\right)+2\arctan\left(\frac{1}{5}\right)+2\arctan\left(\frac{1}{86}\right)-2\arctan\left(\frac{1}{939}\right)-2\arctan\left(\frac{1}{1068}\right)+2\arctan\left(\frac{1}{1764383}\right)$$