M000050

$$\pi=\frac{62324}{3}\arctan\left(\frac{2}{13489}\right)+\frac{19352}{3}\arctan\left(\frac{2}{200779}\right)+2324\arctan\left(\frac{2}{362619}\right)+\frac{3232}{3}\arctan\left(\frac{1}{623098}\right)\frac{-49052}{3}\arctan\left(\frac{1}{734557}\right)+7528\arctan\left(\frac{1}{2634273}\right)+\frac{6424}{3}\arctan\left(\frac{1}{6826318}\right)+9900\arctan\left(\frac{1}{7626068}\right)+\frac{21548}{3}\arctan\left(\frac{1}{21072618}\right)$$
Compact formula62324/3[13489/2] + 19352/3[200779/2] + 2324[362619/2] + 3232/3[623098] - 49052/3[734557] + 7528[2634273] + 6424/3[6826318] + 9900[7626068] + 21548/3[21072618]
Lehmer's measure1.57823
References
MRW (14Aug06) (full reference coming soon)