M000000965

$$\pi=16\arctan\left(\frac{1}{4}\right)-16\arctan\left(\frac{1}{27}\right)-16\arctan\left(\frac{1}{86}\right)-4\arctan\left(\frac{1}{226}\right)+16\arctan\left(\frac{1}{939}\right)+4\arctan\left(\frac{1}{4155}\right)-16\arctan\left(\frac{1}{1764383}\right)$$