A276778 a(n) = floor(log_10(1/error(n))), where error(n) is the error in the n-th iteration of the Salamin-Brent algorithm for computing Pi.

1, 4, 9, 20, 42, 85, 173, 347, 697, 1395, 2792, 5587, 11175, 22352, 44706, 89414, 178830, 357661, 715324, 1430650, 2861303, 5722607, 11445216, 22890435, 45780872, 91561745, 183123492, 301029986, 301029986

Offset

1,2

References

J. M. Borwein and P. B. Borwein, Pi and the AGM, Wiley, 1987.

Links

Table of n, a(n) for n=1..29.

D. H. Bailey, J. M. Borwein, P. B. Borwein, and S. Plouffe, The Quest for Pi, Mathematical Intelligencer, vol. 19, no. 1 (Jan. 1997), 50-57.

Lucas A. Brown, Python program.

Shalosh B. Ekhad, Three New Sequences for the OEIS, in Fond Memory of Jon Borwein (1951-2016); Local copy, pdf file only, no active links

Doron Zeilberger, Jonathan Borwein (1951-2016), a PiONEER of Experimental Mathematics, Experimental Mathematics Seminar, Rutgers University, Sep 15 2016; Local copy, pdf file only, no active links

Crossrefs

Cf. A276779, A276780.

Sequence in context: A284736 A051136 A156321 * A133095 A132175 A019493

Adjacent sequences: A276775 A276776 A276777 * A276779 A276780 A276781

Keyword

nonn,hard,more

Author

Doron Zeilberger, Sep 18 2016

Extensions

Revised definition and terms a(18)-a(29) from Lucas A. Brown, May 05 2023

Status

approved