Some Background on Kanada’s Recent Pi Calculation

in a similar way. This formula was used in numerous computations of π, culminating with Shanks’ computation of π to 707 decimal digits accuracy in 1873 (although it was later found that this result was in error after the 527-th decimal place). With the development of computer technology in the 1950s, π was computed to thousands and then millions of digits. These computations were facilitated by the discovery that highprecision multiplication could be performed rapidly using fast Fourier transform (FFT)s. In spite of these advances, until the 1970s all computer evaluations of π still employed classical formulas, usually one of the Machin-type formulas. Some new infinite series formulas were discovered by Ramanujan around 1910, but these were not well known until quite recently when his writings were widely published. One of these is the formula