M000000847

$$\pi=48\arctan\left(\frac{1}{3}\right)-48\arctan\left(\frac{1}{4}\right)-48\arctan\left(\frac{1}{81}\right)-4\arctan\left(\frac{1}{239}\right)-16\arctan\left(\frac{1}{433}\right)+48\arctan\left(\frac{1}{467}\right)+16\arctan\left(\frac{1}{1875333}\right)$$