M000028

$$\pi=2324\arctan\left(\frac{1}{1252}\right)+3056\arctan\left(\frac{1}{2855}\right)+1064\arctan\left(\frac{1}{5827}\right)+1464\arctan\left(\frac{1}{58898}\right)+780\arctan\left(\frac{1}{110443}\right)+2148\arctan\left(\frac{1}{4841182}\right)-1064\arctan\left(\frac{1}{1561886607}\right)$$
Compact formula2324[1252] + 3056[2855] + 1064[5827] + 1464[58898] + 780[110443] + 2148[4841182] - 1064[1561886607]
Lehmer's measure1.54407
References
Chien-Lih, Hwang. More Machin-type identities, The Mathematical Gazette 81, 120–121, 1997. [DOI: 10.2307/3618793]

HCL (19Jul95)(*1.58160, ΒΆΒΆ1.96453) (full reference coming soon)