M000003588

$$\pi=8\arctan\left(\frac{1}{3}\right)+4\arctan\left(\frac{1}{5}\right)-4\arctan\left(\frac{1}{18}\right)+4\arctan\left(\frac{1}{21}\right)-4\arctan\left(\frac{1}{27}\right)-4\arctan\left(\frac{1}{86}\right)+4\arctan\left(\frac{1}{939}\right)-4\arctan\left(\frac{1}{1764383}\right)$$

Compact formula	`8[3] + 4[5] - 4[18] + 4[21] - 4[27] - 4[86] + 4[939] - 4[1764383]`
Lehmer's measure	6.79157