M000019

$$\pi=152\arctan\left(\frac{1}{47}\right)-56\arctan\left(\frac{1}{610}\right)-24\arctan\left(\frac{2}{296489}\right)+56\arctan\left(\frac{1}{15628852}\right)-28\arctan\left(\frac{1}{54608393}\right)-24\arctan\left(\frac{1}{18677233307}\right)$$
Compact formula152[47] - 56[610] - 24[296489/2] + 56[15628852] - 28[54608393] - 24[18677233307]
Lehmer's measure1.51607
References
ASN (11Sep09)(*1.58112) (full reference coming soon)