M000000505

$$\pi=12\arctan\left(\frac{1}{3}\right)-4\arctan\left(\frac{1}{4}\right)+4\arctan\left(\frac{1}{21}\right)+4\arctan\left(\frac{1}{57}\right)$$

Compact formula	`12[3] - 4[4] + 4[21] + 4[57]`
Lehmer's measure	5.08268