The other two-term Machin-like formulas are Euler's Machin-like formula, Hermann's formula, and Machin's formula.
Hutton's Formula
See also
Euler's Machin-like formula, Hermann's Formula, Machin's Formula, Machin-Like FormulasExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Hutton's Formula." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/HuttonsFormula.html