M000091

$$\pi=69852\arctan\left(\frac{1}{39356}\right)+54796\arctan\left(\frac{1}{51412}\right)+42796\arctan\left(\frac{2}{362619}\right)-6796\arctan\left(\frac{1}{450493}\right)+111644\arctan\left(\frac{1}{1610057}\right)+27340\arctan\left(\frac{1}{6826318}\right)+5476\arctan\left(\frac{1}{7626068}\right)+112376\arctan\left(\frac{1}{21072618}\right)+59220\arctan\left(\frac{1}{103224943}\right)-71172\arctan\left(\frac{1}{2539791558}\right)$$
Compact formula69852[39356] + 54796[51412] + 42796[362619/2] - 6796[450493] + 111644[1610057] + 27340[6826318] + 5476[7626068] + 112376[21072618] + 59220[103224943] - 71172[2539791558]
Lehmer's measure1.61733
References
HCL (29Jun03)(ΒΆΒΆ1.87850) (full reference coming soon)