M000200

$$\pi=64\arctan\left(\frac{1}{21}\right)+12\arctan\left(\frac{1}{239}\right)+16\arctan\left(\frac{1}{347}\right)-16\arctan\left(\frac{1}{361577}\right)$$

Compact formula	`64[21] + 12[239] + 16[347] - 16[361577]`
Lehmer's measure	1.75031
References	Chien-Lih, Hwang. More Machin-type identities, The Mathematical Gazette 81, 120–121, 1997. [DOI: 10.2307/3618793] `MRW (1980)(*1.86105)` (full reference coming soon) Download references as BibTeΧ