Chronology of computation of π
The table below is a brief chronology of computed numerical values of, or bounds on, the mathematical constant pi (π). For more detailed explanations for some of these calculations, see Approximations of π.
Part of a series of articles on the |
mathematical constant π |
---|
3.1415926535897932384626433... |
Uses |
Properties |
Value |
People |
History |
In culture |
Related topics |
The last 100 decimal digits[1] of the latest 2022 world record computation are:[2]
4658718895 1242883556 4671544483 9873493812 1206904813 2656719174 5255431487 2142102057 7077336434 3095295560
Before 1400
Date | Who | Description/Computation method used | Value | Decimal places (world records in bold) |
---|---|---|---|---|
2000? BC | Ancient Egyptians[3] | 4 × (8⁄9)2 | 3.1605... | 1 |
2000? BC | Ancient Babylonians[3] | 3 + 1⁄8 | 3.125 | 1 |
2000? BC | Ancient Sumerians[4] | 3 + 23/216 | 3.1065 | 1 |
1200? BC | Ancient Chinese[3] | 3 | 3 | 0 |
800–600 BC | Shatapatha Brahmana – 7.1.1.18 [5] | Instructions on how to construct a circular altar from oblong bricks:
"He puts on (the circular site) four (bricks) running eastwards 1; two behind running crosswise (from south to north), and two (such) in front. Now the four which he puts on running eastwards are the body; and as to there being four of these, it is because this body (of ours) consists, of four parts 2. The two at the back then are the thighs; and the two in front the arms; and where the body is that (includes) the head."[6] |
25⁄8 = 3.125 | 1 |
800? BC | Shulba Sutras[7] | (6⁄(2 + √2))2 | 3.088311 ... | 0 |
550? BC | Bible (1 Kings 7:23)[3] | "...a molten sea, ten cubits from the one brim to the other: it was round all about,... a line of thirty cubits did compass it round about" | 3 | 0 |
434 BC | Anaxagoras attempted to square the circle[10] | compass and straightedge | Anaxagoras didn't offer any solution | 0 |
400 BC to 400 AD | Vyasa[11] |
verses: 6.12.40-45 of the Bhishma Parva of the Mahabharata offer: |
3 | 0 |
c. 250 BC | Archimedes[3] | 223⁄71 < π < 22⁄7 | 3.140845... < π < 3.142857... | 2 |
15 BC | Vitruvius[8] | 25⁄8 | 3.125 | 1 |
between 1 and 5 | Liu Xin[8][12][13] | Unknown method giving a figure for a jialiang which implies a value for π π ≈ 162⁄(√50+0.095)2. | 3.1547... | 1 |
130 | Zhang Heng (Book of the Later Han)[3] | √10 = 3.162277... 736⁄232 |
3.1622... | 1 |
150 | Ptolemy[3] | 377⁄120 | 3.141666... | 3 |
250 | Wang Fan[3] | 142⁄45 | 3.155555... | 1 |
263 | Liu Hui[3] | 3.141024 < π < 3.142074 3927⁄1250 |
3.1416 | 3 |
400 | He Chengtian[8] | 111035⁄35329 | 3.142885... | 2 |
480 | Zu Chongzhi[3] | 3.1415926 < π < 3.1415927 355⁄113 |
3.1415926 | 7 |
499 | Aryabhata[3] | 62832⁄20000 | 3.1416 | 3 |
640 | Brahmagupta[3] | √10 | 3.162277... | 1 |
800 | Al Khwarizmi[3] | 3.1416 | 3 | |
1150 | Bhāskara II[8] | 3927⁄1250 and 754⁄240 | 3.1416 | 3 |
1220 | Fibonacci[3] | 3.141818 | 3 | |
1320 | Zhao Youqin[8] | 3.141592 | 6 |
1400–1949
Date | Who | Note | Decimal places (world records in bold) |
---|---|---|---|
All records from 1400 onwards are given as the number of correct decimal places. | |||
1400 | Madhava of Sangamagrama | Discovered the infinite power series expansion of π, now known as the Leibniz formula for pi[14] |
10 |
1424 | Jamshīd al-Kāshī[15] | 16 | |
1573 | Valentinus Otho | 355⁄113 | 6 |
1579 | François Viète[16] | 9 | |
1593 | Adriaan van Roomen[17] | 15 | |
1596 | Ludolph van Ceulen | 20 | |
1615 | 32 | ||
1621 | Willebrord Snell (Snellius) | Pupil of Van Ceulen | 35 |
1630 | Christoph Grienberger[18][19] | 38 | |
1654 | Christiaan Huygens | Used a geometrical method equivalent to Richardson extrapolation | 10 |
1665 | Isaac Newton[3] | 16 | |
1681 | Takakazu Seki[20] | 11 16 | |
1699 | Abraham Sharp[3] | Calculated pi to 72 digits, but not all were correct | 71 |
1706 | John Machin[3] | 100 | |
1706 | William Jones | Introduced the Greek letter 'π' | |
1719 | Thomas Fantet de Lagny[3] | Calculated 127 decimal places, but not all were correct | 112 |
1721 | Anonymous | Calculation made in Philadelphia, Pennsylvania, giving the value of pi to 154 digits, 152 of which were correct. First discovered by F. X. von Zach in a library in Oxford, England in the 1780s, and reported to Jean-Étienne Montucla, who published an account of it.[21] | 152 |
1722 | Toshikiyo Kamata | 24 | |
1722 | Katahiro Takebe | 41 | |
1739 | Yoshisuke Matsunaga | 51 | |
1748 | Leonhard Euler | Used the Greek letter 'π' in his book Introductio in Analysin Infinitorum and assured its popularity. | |
1761 | Johann Heinrich Lambert | Proved that π is irrational | |
1775 | Euler | Pointed out the possibility that π might be transcendental | |
1789 | Jurij Vega[22] | Calculated 140 decimal places, but not all were correct | 126 |
1794 | Adrien-Marie Legendre | Showed that π2 (and hence π) is irrational, and mentioned the possibility that π might be transcendental. | |
1824 | William Rutherford[3] | Calculated 208 decimal places, but not all were correct | 152 |
1844 | Zacharias Dase and Strassnitzky[3] | Calculated 205 decimal places, but not all were correct | 200 |
1847 | Thomas Clausen[3] | Calculated 250 decimal places, but not all were correct | 248 |
1853 | Lehmann[3] | 261 | |
1853 | Rutherford[3] | 440 | |
1853 | William Shanks[23] | Expanded his calculation to 707 decimal places in 1873, but an error introduced at the beginning of his new calculation rendered all of the subsequent digits incorrect (the error was found by D. F. Ferguson in 1946). | 527 |
1882 | Ferdinand von Lindemann | Proved that π is transcendental (the Lindemann–Weierstrass theorem) | |
1897 | The U.S. state of Indiana | Came close to legislating the value 3.2 (among others) for π. House Bill No. 246 passed unanimously. The bill stalled in the state Senate due to a suggestion of possible commercial motives involving publication of a textbook.[24] | 0 |
1910 | Srinivasa Ramanujan | Found several rapidly converging infinite series of π, which can compute 8 decimal places of π with each term in the series. Since the 1980s, his series have become the basis for the fastest algorithms currently used by Yasumasa Kanada and the Chudnovsky brothers to compute π. | |
1946 | D. F. Ferguson | Most digits ever calculated by hand. | 620 |
1947 | Ivan Niven | Gave a very elementary proof that π is irrational | |
January 1947 | D. F. Ferguson | Made use of a desk calculator | 710 |
September 1947 | D. F. Ferguson | Desk calculator | 808 |
1949 | Levi B. Smith and John Wrench | Made use of a desk calculator | 1,120 |
1949–2009
Date | Who | Implementation | Time | Decimal places (world records in bold) |
---|---|---|---|---|
All records from 1949 onwards were calculated with electronic computers. | ||||
1949 | G. W. Reitwiesner et al. | The first to use an electronic computer (the ENIAC) to calculate π [25] | 70 hours | 2,037 |
1953 | Kurt Mahler | Showed that π is not a Liouville number | ||
1954 | S. C. Nicholson & J. Jeenel | Using the NORC[26] | 13 minutes | 3,093 |
1957 | George E. Felton | Ferranti Pegasus computer (London), calculated 10,021 digits, but not all were correct[27][28] | 33 hours | 7,480 |
January 1958 | Francois Genuys | IBM 704[29] | 1.7 hours | 10,000 |
May 1958 | George E. Felton | Pegasus computer (London) | 33 hours | 10,021 |
1959 | Francois Genuys | IBM 704 (Paris)[30] | 4.3 hours | 16,167 |
1961 | Daniel Shanks and John Wrench | IBM 7090 (New York)[31] | 8.7 hours | 100,265 |
1961 | J.M. Gerard | IBM 7090 (London) | 39 minutes | 20,000 |
February 1966 | Jean Guilloud and J. Filliatre | IBM 7030 (Paris)[28] | 41.92 hours | 250,000 |
1967 | Jean Guilloud and M. Dichampt | CDC 6600 (Paris) | 28 hours | 500,000 |
1973 | Jean Guilloud and Martine Bouyer | CDC 7600 | 23.3 hours | 1,001,250 |
1981 | Kazunori Miyoshi and Yasumasa Kanada | FACOM M-200[28] | 137.3 hours | 2,000,036 |
1981 | Jean Guilloud | Not known | 2,000,050 | |
1982 | Yoshiaki Tamura | MELCOM 900II[28] | 7.23 hours | 2,097,144 |
1982 | Yoshiaki Tamura and Yasumasa Kanada | HITAC M-280H[28] | 2.9 hours | 4,194,288 |
1982 | Yoshiaki Tamura and Yasumasa Kanada | HITAC M-280H[28] | 6.86 hours | 8,388,576 |
1983 | Yasumasa Kanada, Sayaka Yoshino and Yoshiaki Tamura | HITAC M-280H[28] | <30 hours | 16,777,206 |
October 1983 | Yasunori Ushiro and Yasumasa Kanada | HITAC S-810/20 | 10,013,395 | |
October 1985 | Bill Gosper | Symbolics 3670 | 17,526,200 | |
January 1986 | David H. Bailey | CRAY-2[28] | 28 hours | 29,360,111 |
September 1986 | Yasumasa Kanada, Yoshiaki Tamura | HITAC S-810/20[28] | 6.6 hours | 33,554,414 |
October 1986 | Yasumasa Kanada, Yoshiaki Tamura | HITAC S-810/20[28] | 23 hours | 67,108,839 |
January 1987 | Yasumasa Kanada, Yoshiaki Tamura, Yoshinobu Kubo and others | NEC SX-2[28] | 35.25 hours | 134,214,700 |
January 1988 | Yasumasa Kanada and Yoshiaki Tamura | HITAC S-820/80[32] | 5.95 hours | 201,326,551 |
May 1989 | Gregory V. Chudnovsky & David V. Chudnovsky | CRAY-2 & IBM 3090/VF | 480,000,000 | |
June 1989 | Gregory V. Chudnovsky & David V. Chudnovsky | IBM 3090 | 535,339,270 | |
July 1989 | Yasumasa Kanada and Yoshiaki Tamura | HITAC S-820/80 | 536,870,898 | |
August 1989 | Gregory V. Chudnovsky & David V. Chudnovsky | IBM 3090 | 1,011,196,691 | |
19 November 1989 | Yasumasa Kanada and Yoshiaki Tamura | HITAC S-820/80[33] | 1,073,740,799 | |
August 1991 | Gregory V. Chudnovsky & David V. Chudnovsky | Homemade parallel computer (details unknown, not verified) [34][33] | 2,260,000,000 | |
18 May 1994 | Gregory V. Chudnovsky & David V. Chudnovsky | New homemade parallel computer (details unknown, not verified) | 4,044,000,000 | |
26 June 1995 | Yasumasa Kanada and Daisuke Takahashi | HITAC S-3800/480 (dual CPU) [35] | 3,221,220,000 | |
1995 | Simon Plouffe | Finds a formula that allows the nth hexadecimal digit of pi to be calculated without calculating the preceding digits. | ||
28 August 1995 | Yasumasa Kanada and Daisuke Takahashi | HITAC S-3800/480 (dual CPU) [36][37] | 56.74 hours? | 4,294,960,000 |
11 October 1995 | Yasumasa Kanada and Daisuke Takahashi | HITAC S-3800/480 (dual CPU) [38][37] | 116.63 hours | 6,442,450,000 |
6 July 1997 | Yasumasa Kanada and Daisuke Takahashi | HITACHI SR2201 (1024 CPU) [39][40] | 29.05 hours | 51,539,600,000 |
5 April 1999 | Yasumasa Kanada and Daisuke Takahashi | HITACHI SR8000 (64 of 128 nodes) [41][42] | 32.9 hours | 68,719,470,000 |
20 September 1999 | Yasumasa Kanada and Daisuke Takahashi | HITACHI SR8000/MPP (128 nodes) [43][44] | 37.35 hours | 206,158,430,000 |
24 November 2002 | Yasumasa Kanada & 9 man team | HITACHI SR8000/MPP (64 nodes), Department of Information Science at the University of Tokyo in Tokyo, Japan[45] | 600 hours | 1,241,100,000,000 |
29 April 2009 | Daisuke Takahashi et al. | T2K Open Supercomputer (640 nodes), single node speed is 147.2 gigaflops, computer memory is 13.5 terabytes, Gauss–Legendre algorithm, Center for Computational Sciences at the University of Tsukuba in Tsukuba, Japan[46] | 29.09 hours | 2,576,980,377,524 |
2009–present
Date | Who | Implementation | Time | Decimal places (world records in bold) |
---|---|---|---|---|
All records from Dec 2009 onwards are calculated and verified on servers and/or home computers with commercially available parts. | ||||
31 December 2009 | Fabrice Bellard |
|
131 days | 2,699,999,990,000 |
2 August 2010 | Shigeru Kondo[49] |
|
90 days | 5,000,000,000,000 |
17 October 2011 | Shigeru Kondo[52] |
|
371 days | 10,000,000,000,050 |
28 December 2013 | Shigeru Kondo[53] |
|
94 days | 12,100,000,000,050 |
8 October 2014 | Sandon Nash Van Ness "houkouonchi"[54] |
|
208 days | 13,300,000,000,000 |
11 November 2016 | Peter Trueb[55][56] |
|
105 days | 22,459,157,718,361 = ⌊πe × 1012⌋ |
14 March 2019 | Emma Haruka Iwao[58] |
|
121 days | 31,415,926,535,897 = ⌊π × 1013⌋ |
29 January 2020 | Timothy Mullican[59][60] |
|
303 days | 50,000,000,000,000 |
14 August 2021 | Team DAViS of the University of Applied Sciences of the Grisons[61][62] |
|
108 days | 62,831,853,071,796 = ⌊2π × 1013⌋ |
21 March 2022 | Emma Haruka Iwao[63][64] |
|
158 days | 100,000,000,000,000 |
See also
References
- The last digit shown here is the 100,000,000,000,000th digit of π.
- "Validation File". Retrieved 2022-06-09.
- David H. Bailey; Jonathan M. Borwein; Peter B. Borwein; Simon Plouffe (1997). "The quest for pi" (PDF). Mathematical Intelligencer. 19 (1): 50–57. doi:10.1007/BF03024340. S2CID 14318695.
- "Origins: 3.14159265…". Biblical Archaeology Society. 2022-03-14. Retrieved 2022-06-08.
- Eggeling, Julius (1882–1900). The Satapatha-brahmana, according to the text of the Madhyandina school. Princeton Theological Seminary Library. Oxford, The Clarendon Press. pp. 302–303.
{{cite book}}
: CS1 maint: date and year (link) - The Sacred Books of the East: The Satapatha-Brahmana, pt. 3. Clarendon Press. 1894. p. 303. This article incorporates text from this source, which is in the public domain.
- "4 II. Sulba Sutras". www-history.mcs.st-and.ac.uk.
- Ravi P. Agarwal; Hans Agarwal; Syamal K. Sen (2013). "Birth, growth and computation of pi to ten trillion digits". Advances in Difference Equations. 2013: 100. doi:10.1186/1687-1847-2013-100.
- Plofker, Kim (2009). Mathematics in India. Princeton University Press. p. 18. ISBN 978-0691120676.
- Wilson, David (2000). "The History of Pi". sites.math.rutgers.edu. University Of Rutgers. Archived from the original on 7 May 2023.
- Jadhav, Dipak (2018-01-01). "On The Value Implied In The Data Referred To In The Mahābhārata for π". Vidyottama Sanatana: International Journal of Hindu Science and Religious Studies. 2 (1): 18. doi:10.25078/ijhsrs.v2i1.511. ISSN 2550-0651. S2CID 146074061.
- 趙良五 (1991). 中西數學史的比較. 臺灣商務印書館. ISBN 978-9570502688 – via Google Books.
- Needham, Joseph (1986). Science and Civilization in China: Volume 3, Mathematics and the Sciences of the Heavens and the Earth. Taipei: Caves Books, Ltd. Volume 3, 100.
- Bag, A. K. (1980). "Indian Literature on Mathematics During 1400–1800 A.D." (PDF). Indian Journal of History of Science. 15 (1): 86.
π ≈ 2,827,433,388,233/9×10−11 = 3.14159 26535 92222..., good to 10 decimal places.
- approximated 2π to 9 sexagesimal digits. Al-Kashi, author: Adolf P. Youschkevitch, chief editor: Boris A. Rosenfeld, p. 256 O'Connor, John J.; Robertson, Edmund F., "Ghiyath al-Din Jamshid Mas'ud al-Kashi", MacTutor History of Mathematics Archive, University of St Andrews Azarian, Mohammad K. (2010). "Al-Risāla Al-Muhītīyya: A Summary". Missouri Journal of Mathematical Sciences. 22 (2): 64–85. doi:10.35834/mjms/1312233136.
- Viète, François (1579). Canon mathematicus seu ad triangula : cum adpendicibus (in Latin).
- Romanus, Adrianus (1593). Ideae mathematicae pars prima, sive methodus polygonorum (in Latin). apud Ioannem Keerbergium. hdl:2027/ucm.5320258006.
- Grienbergerus, Christophorus (1630). Elementa Trigonometrica (PDF) (in Latin). Archived from the original (PDF) on 2014-02-01.
- Hobson, Ernest William (1913). 'Squaring the Circle': a History of the Problem (PDF). Cambridge University Press. p. 27.
- Yoshio, Mikami; Eugene Smith, David (2004) [1914]. A History of Japanese Mathematics (paperback ed.). Dover Publications. ISBN 0-486-43482-6.
- Benjamin Wardhaugh, "Filling a Gap in the History of π: An Exciting Discovery", Mathematical Intelligencer 38(1) (2016), 6-7
- Vega, Géorge (1795) [1789]. "Detérmination de la demi-circonférence d'un cercle dont le diameter est = 1, exprimée en 140 figures decimals". Supplement. Nova Acta Academiae Scientiarum Petropolitanae. 11: 41–44.
Sandifer, Ed (2006). "Why 140 Digits of Pi Matter" (PDF). Southern Connecticut State University. Archived from the original (PDF) on 2012-02-04.
- Hayes, Brian (September 2014). "Pencil, Paper, and Pi". American Scientist. Vol. 102, no. 5. p. 342. doi:10.1511/2014.110.342. Retrieved 13 February 2022.
- Lopez-Ortiz, Alex (February 20, 1998). "Indiana Bill sets value of Pi to 3". the news.answers WWW archive. Department of Information and Computing Sciences, Utrecht University. Archived from the original on 2005-01-09. Retrieved 2009-02-01.
- Reitwiesner, G. (1950). "An ENIAC determination of π and e to more than 2000 decimal places". MTAC. 4: 11–15. doi:10.1090/S0025-5718-1950-0037597-6.
- Nicholson, S. C.; Jeenel, J. (1955). "Some comments on a NORC computation of π". MTAC. 9: 162–164. doi:10.1090/S0025-5718-1955-0075672-5.
- G. E. Felton, "Electronic computers and mathematicians," Abbreviated Proceedings of the Oxford Mathematical Conference for Schoolteachers and Industrialists at Trinity College, Oxford, April 8–18, 1957, pp. 12–17, footnote pp. 12–53. This published result is correct to only 7480D, as was established by Felton in a second calculation, using formula (5), completed in 1958 but apparently unpublished. For a detailed account of calculations of π see Wrench, J. W. Jr. (1960). "The evolution of extended decimal approximations to π". The Mathematics Teacher. 53 (8): 644–650. doi:10.5951/MT.53.8.0644. JSTOR 27956272.
- Arndt, Jörg; Haenel, Christoph (2001). Pi - Unleashed. Springer. ISBN 978-3-642-56735-3.
- Genuys, F. (1958). "Dix milles decimales de π". Chiffres. 1: 17–22.
- This unpublished value of x to 16167D was computed on an IBM 704 system at the French Alternative Energies and Atomic Energy Commission in Paris, by means of the program of Genuys
- Shanks, Daniel; Wrench, John W. J.r (1962). "Calculation of π to 100,000 decimals". Mathematics of Computation. 16 (77): 76–99. doi:10.1090/S0025-5718-1962-0136051-9.
- Kanada, Y. (November 1988). "Vectorization of multiple-precision arithmetic program and 201,326,000 decimal digits of pi calculation". Proceedings Supercomputing Vol.II: Science and Applications. pp. 117–128 vol.2. doi:10.1109/SUPERC.1988.74139. ISBN 0-8186-8923-4. S2CID 122820709.
- "Computers". Science News. 24 August 1991. Retrieved 2022-08-04.
- Bigger slices of Pi (determination of the numerical value of pi reaches 2.16 billion decimal digits) Science News 24 August 1991 http://www.encyclopedia.com/doc/1G1-11235156.html
- ftp://pi.super-computing.org/README.our_last_record_3b%5B%5D
- ftp://pi.super-computing.org/README.our_last_record_4b%5B%5D
- "GENERAL COMPUTATIONAL UPDATE". www.cecm.sfu.ca. Retrieved 2022-08-04.
- ftp://pi.super-computing.org/README.our_last_record_6b
- ftp://pi.super-computing.org/README.our_last_record_51b%5B%5D
- "Record for pi : 51.5 billion decimal digits". 2005-12-24. Archived from the original on 2005-12-24. Retrieved 2022-08-04.
- ftp://pi.super-computing.org/README.our_last_record_68b%5B%5D
- Kanada, Yasumasa. "plouffe.fr/simon/constants/Pi68billion.txt". www.plouffe.fr. Archived from the original on 5 August 2022.
- ftp://pi.super-computing.org/README.our_latest_record_206b%5B%5D
- "Record for pi : 206 billion decimal digits". www.cecm.sfu.ca. Retrieved 2022-08-04.
- "Archived copy". Archived from the original on 2011-03-12. Retrieved 2010-07-08.
{{cite web}}
: CS1 maint: archived copy as title (link) - "Archived copy". Archived from the original on 2009-08-23. Retrieved 2009-08-18.
{{cite web}}
: CS1 maint: archived copy as title (link) - "Fabrice Bellard's Home Page". bellard.org. Retrieved 28 August 2015.
- Bellard, Fabrice (11 Feb 2010). "Computation of 2700 billion decimal digits of Pi using a Desktop Computer" (PDF). S2CID 12242318.
{{cite journal}}
: Cite journal requires|journal=
(help) - "PI-world". calico.jp. Archived from the original on 31 August 2015. Retrieved 28 August 2015.
- "y-cruncher – A Multi-Threaded Pi Program". numberworld.org. Retrieved 28 August 2015.
- "Pi – 5 Trillion Digits". numberworld.org. Retrieved 28 August 2015.
- "Pi – 10 Trillion Digits". numberworld.org. Retrieved 28 August 2015.
- "Pi – 12.1 Trillion Digits". numberworld.org. Retrieved 28 August 2015.
- "y-cruncher – A Multi-Threaded Pi Program". numberworld.org. Retrieved 14 March 2018.
- "pi2e". pi2e.ch. Retrieved 15 November 2016.
- Alexander J. Yee. "y-cruncher – A Multi-Threaded Pi Program". numberworld.org. Retrieved 15 November 2016.
- "Hexadecimal Digits are Correct! – pi2e trillion digits of pi". pi2e.ch. 31 October 2016. Retrieved 15 November 2016.
- "Google Cloud Topples the Pi Record". Retrieved 14 March 2019.
- "The Pi Record Returns to the Personal Computer". Retrieved 30 January 2020.
- "Calculating Pi: My attempt at breaking the Pi World Record". 26 June 2019. Retrieved 30 January 2020.
- "Pi-Challenge - world record attempt by UAS Grisons - University of Applied Sciences of the Grisons". www.fhgr.ch. 2021-08-14. Archived from the original on 2021-08-17. Retrieved 2021-08-17.
- "Die FH Graubünden kennt Pi am genauesten – Weltrekord! - News - FH Graubünden". www.fhgr.ch (in German). 2021-08-16. Archived from the original on 2021-08-17. Retrieved 2021-08-17.
- "Calculating 100 trillion digits of pi on Google Cloud". Google Cloud Blog. Retrieved 2022-06-10.
- "News (2019)". numberworld.org. Retrieved 2022-06-10.
External links
- Borwein, Jonathan, "The Life of Pi"
- Kanada Laboratory home page
- Stu's Pi page
- Takahashi's page