Bailey-Borwein-Plouffe formula

The BBP (named after Bailey-Borwein-Plouffe) is a formula for calculating pi discovered by Simon Plouffe in 1995, π = sum_(n = 0)^∞(4/(8n + 1) - 2/(8n + 4) - 1/(8n + 5) - 1/(8n + 6))(1/16)^n. Amazingly, this formula is a digit-extraction algorithm for π in base 16. Following the discovery of this and related formulas, similar formulas in other bases were investigated. This class of formulas are now known as BBP-type formulas.

BBP-type formula | pi