M000382

$$\pi=640\arctan\left(\frac{1}{200}\right)-4\arctan\left(\frac{1}{239}\right)-16\arctan\left(\frac{1}{515}\right)-32\arctan\left(\frac{1}{4030}\right)-64\arctan\left(\frac{1}{50105}\right)-64\arctan\left(\frac{1}{62575}\right)-128\arctan\left(\frac{1}{500150}\right)-320\arctan\left(\frac{1}{4000300}\right)$$