M000023

$$\pi=508\arctan\left(\frac{1}{192}\right)+516\arctan\left(\frac{1}{1068}\right)+244\arctan\left(\frac{1}{11379}\right)-400\arctan\left(\frac{2}{81487}\right)+176\arctan\left(\frac{1}{173932}\right)-244\arctan\left(\frac{1}{3819719818}\right)$$
Compact formula508[192] + 516[1068] + 244[11379] - 400[81487/2] + 176[173932] - 244[3819719818]
Lehmer's measure1.52679
References
ASN (2007-8)(*1.57880) (full reference coming soon)