Machin-like formulae
M000480
$$\pi=176\arctan\left(\frac{1}{57}\right)-20\arctan\left(\frac{1}{239}\right)+192\arctan\left(\frac{1}{1511}\right)+48\arctan\left(\frac{1}{4443}\right)-96\arctan\left(\frac{1}{1724900182}\right)$$
Compact formula
176[57] - 20[239] + 192[1511] + 48[4443] - 96[1724900182]
Lehmer's measure
1.68691
References
Chien-Lih, Hwang. More Machin-type identities,
The Mathematical Gazette
81, 120–121, 1997. [DOI:
10.2307/3618793
]
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