Machin-like formulae
M000001: Machin's formula
$$\pi=16\arctan\left(\frac{1}{5}\right)-4\arctan\left(\frac{1}{239}\right)$$
Name
Machin's formula
Compact formula
16[5] - 4[239]
Lehmer's measure
1.85112
References
*MACHIN (1706)
(full reference coming soon)