Machin-like formulae
M000366
$$\pi=16\arctan\left(\frac{1}{5}\right)-8\arctan\left(\frac{1}{577}\right)-4\arctan\left(\frac{1}{1393}\right)$$
Compact formula
16[5] - 8[577] - 4[1393]
Lehmer's measure
2.11091
References
STØRMER (1896)
(full reference coming soon)