Machin-like formulae
M000047
$$\pi=684\arctan\left(\frac{1}{239}\right)+96\arctan\left(\frac{2}{1511}\right)+752\arctan\left(\frac{1}{4443}\right)-704\arctan\left(\frac{2}{86161}\right)-176\arctan\left(\frac{1}{740943}\right)-352\arctan\left(\frac{1}{5926518}\right)$$
Compact formula
684[239] + 96[1511/2] + 752[4443] - 704[86161/2] - 176[740943] - 352[5926518]
Lehmer's measure
1.57583
References
MRW (1Jul10)
(full reference coming soon)