Machin-like formulae
M000000508
$$\pi=16\arctan\left(\frac{1}{4}\right)-16\arctan\left(\frac{1}{21}\right)-4\arctan\left(\frac{1}{241}\right)-4\arctan\left(\frac{1}{28800}\right)$$
Compact formula
16[4] - 16[21] - 4[241] - 4[28800]
Lehmer's measure
3.06132