Machin-like formulae
M000086
$$\pi=176\arctan\left(\frac{1}{57}\right)-20\arctan\left(\frac{1}{239}\right)+96\arctan\left(\frac{2}{1511}\right)+48\arctan\left(\frac{1}{4443}\right)$$
Compact formula
176[57] - 20[239] + 96[1511/2] + 48[4443]
Lehmer's measure
1.61155
References
HCL (21Jan95)
(full reference coming soon)