Machin-like formulae
M000262
$$\pi=48\arctan\left(\frac{1}{18}\right)+32\arctan\left(\frac{1}{109}\right)+44\arctan\left(\frac{1}{239}\right)-32\arctan\left(\frac{1}{6826318}\right)$$
Compact formula
48[18] + 32[109] + 44[239] - 32[6826318]
Lehmer's measure
1.85422
References
Chien-Lih, Hwang. More Machin-type identities,
The Mathematical Gazette
81, 120–121, 1997. [DOI:
10.2307/3618793
]
ARNDT (1993)
(full reference coming soon)
Download references as BibTeΧ