Machin-like formulae
M000052
$$\pi=508\arctan\left(\frac{1}{192}\right)+516\arctan\left(\frac{1}{1068}\right)+244\arctan\left(\frac{1}{11432}\right)-400\arctan\left(\frac{2}{81487}\right)+176\arctan\left(\frac{1}{173932}\right)+244\arctan\left(\frac{1}{2456007}\right)$$
Compact formula
508[192] + 516[1068] + 244[11432] - 400[81487/2] + 176[173932] + 244[2456007]
Lehmer's measure
1.57880
References
MRW (***)
(full reference coming soon)