M000000018

$$\pi=732\arctan\left(\frac{1}{239}\right)+128\arctan\left(\frac{1}{1023}\right)-272\arctan\left(\frac{1}{5832}\right)+48\arctan\left(\frac{1}{110443}\right)-48\arctan\left(\frac{1}{4841182}\right)-400\arctan\left(\frac{1}{6826318}\right)$$