M000000562

$$\pi=6\arctan\left(\frac{1}{2}\right)+2\arctan\left(\frac{1}{5}\right)-2\arctan\left(\frac{1}{31}\right)+2\arctan\left(\frac{1}{68}\right)$$

Compact formula	`6[2] + 2[5] - 2[31] + 2[68]`
Lehmer's measure	5.96883