Machin-like formulae
M000000501
$$\pi=16\arctan\left(\frac{1}{4}\right)-16\arctan\left(\frac{1}{21}\right)-4\arctan\left(\frac{1}{240}\right)-4\arctan\left(\frac{1}{57361}\right)$$
Compact formula
16[4] - 16[21] - 4[240] - 4[57361]
Lehmer's measure
3.04754