M000000023

$$\pi=508\arctan\left(\frac{1}{192}\right)+516\arctan\left(\frac{1}{1068}\right)+244\arctan\left(\frac{1}{11379}\right)-400\arctan\left(\frac{2}{81487}\right)+176\arctan\left(\frac{1}{173932}\right)-244\arctan\left(\frac{1}{3819719818}\right)$$