Machin-like formulae
M000340
$$\pi=16\arctan\left(\frac{1}{5}\right)-4\arctan\left(\frac{1}{240}\right)-4\arctan\left(\frac{1}{57361}\right)$$
Compact formula
16[5] - 4[240] - 4[57361]
Lehmer's measure
2.06095
References
STØRMER (1896)
(full reference coming soon)