M000003526

$$\pi=16\arctan\left(\frac{1}{2}\right)-16\arctan\left(\frac{1}{5}\right)+8\arctan\left(\frac{1}{12}\right)-8\arctan\left(\frac{1}{14}\right)-16\arctan\left(\frac{1}{21}\right)-16\arctan\left(\frac{1}{47}\right)-8\arctan\left(\frac{1}{70}\right)+4\arctan\left(\frac{1}{1393}\right)$$

Compact formula	`16[2] - 16[5] + 8[12] - 8[14] - 16[21] - 16[47] - 8[70] + 4[1393]`
Lehmer's measure	8.76613