Geometric Illustration of Machin-Like Formulas
This Demonstration illustrates geometrically some Machin-like formulas for computing the number . A Gregory number is , where is a rational number. Since , Gregory numbers arise in the determination of Machin-like formulas for computing the number .[more]
Størmer's numbers are the positive whole numbers for which the largest prime factor of is at least . Størmer showed that every Gregory number , where is a Störmer number, can be uniquely expressed as an integer linear combination of smaller .[less]
J. H. Conway and R. K. Guy, The Book of Numbers, New York: Copernicus Books, 2006 pp. 244–247.