Borwein's algorithm

This and other algorithms can be found in the book Pi and the AGM – A Study in Analytic Number Theory and Computational Complexity.

Start by setting[2] Then Each additional term of the partial sum yields approximately 25 digits.

Start by setting[3] Then Each additional term of the series yields approximately 50 digits.

The algorithm is not self-correcting; each iteration must be performed with the desired number of correct digits for π's final result.

The algorithm is not self-correcting; each iteration must be performed with the desired number of correct digits for π's final result.