A fun related thread on math stackexchange which has several examples of series which converge quickly to pi: https://math.stackexchange.com/questions/14113/ser

A fun related thread on math stackexchange which has several examples of series which converge quickly to pi: https://math.stackexchange.com/questions/14113/series-that-converge-to-pi-quickly https://math.stackexchange.com/questions/14113/series-that-c... edit: There also some nice formulae for quick convergence in this article: https://julialang.org/blog/2017/03/piday https://julialang.org/blog/2017/03/piday