Just finished calculating pi to 30 trillion places.

[Pete]

I haven't researched what super-computers use to calculate pi, but my guess, after testing is that Leibniz formula isn't it! Of course if the one you posted actually has a flaw, it wouldn't be used, either.

I'm not planning on using this to calculate pi accurately at all. I thought it would be fun to throw together, since some of a different discussion thread evolved into a discussion about pi. I also realized this would be a great stress test for my string math routine.

Pete