M000000075

$$\pi=2548\arctan\left(\frac{1}{1068}\right)+1524\arctan\left(\frac{1}{2436}\right)+3028\arctan\left(\frac{1}{26307}\right)+1368\arctan\left(\frac{2}{81487}\right)-1768\arctan\left(\frac{1}{78813}\right)+684\arctan\left(\frac{1}{173932}\right)+508\arctan\left(\frac{1}{15996882}\right)$$