M000000314

$$\pi=48\arctan\left(\frac{1}{26}\right)+80\arctan\left(\frac{1}{57}\right)-20\arctan\left(\frac{1}{239}\right)-48\arctan\left(\frac{1}{2057}\right)$$

Compact formula	`48[26] + 80[57] - 20[239] - 48[2057]`
Lehmer's measure	1.99851
References	Wetherfield, Michael Roby and Chien-Lih, Hwang. Computing pi: Lists of Machin-type (inverse cotangent) identities for pi/4, [Online; accessed 04-February-2024], 2013. [web.archive.org/web/20240204042153/http] [Found by HCL on 26 January 1995.] Download references as BibTeΧ