M000017

$$\pi=508\arctan\left(\frac{1}{239}\right)+1024\arctan\left(\frac{1}{1068}\right)+752\arctan\left(\frac{1}{11379}\right)-400\arctan\left(\frac{2}{81487}\right)+176\arctan\left(\frac{1}{173932}\right)-752\arctan\left(\frac{1}{3819719818}\right)$$
Compact formula508[239] + 1024[1068] + 752[11379] - 400[81487/2] + 176[173932] - 752[3819719818]
Lehmer's measure1.50928
References
ASN (2007-8)(*1.56129) (full reference coming soon)