M000089

$$\pi=18620\arctan\left(\frac{2}{13489}\right)+6464\arctan\left(\frac{2}{47239}\right)+10760\arctan\left(\frac{1}{96348}\right)+2324\arctan\left(\frac{2}{362619}\right)-14196\arctan\left(\frac{1}{734557}\right)+1064\arctan\left(\frac{1}{6826318}\right)+13132\arctan\left(\frac{1}{7626068}\right)+8260\arctan\left(\frac{1}{21072618}\right)-7528\arctan\left(\frac{1}{26157373}\right)$$
Compact formula18620[13489/2] + 6464[47239/2] + 10760[96348] + 2324[362619/2] - 14196[734557] + 1064[6826318] + 13132[7626068] + 8260[21072618] - 7528[26157373]
Lehmer's measure1.61410
References
MRW (14Aug06) (full reference coming soon)