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Search: a096762 -id:a096762
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Positions of the digit '2' in the decimal expansion of Pi (where positions 0, 1, 2,... refer to the digits 3, 1, 4,...).
+10
26
6, 16, 21, 28, 33, 53, 63, 73, 76, 83, 89, 93, 102, 112, 114, 135, 136, 140, 149, 160, 165, 173, 185, 186, 203, 221, 229, 241, 244, 260, 275, 280, 289, 292, 298, 302, 326, 329, 333, 335, 337, 354, 374, 380, 406, 423, 435, 456, 462, 477, 479, 484, 485, 500
OFFSET
1,1
COMMENTS
The first few primes in this sequence are 53, 73, 83, 89, 149, 173, 229, 241, 337, 479, 571, 613, 661, 757, 829, 877, 911, 977, 991, ... - M. F. Hasler, Jul 28 2024
LINKS
Eric Weisstein's World of Mathematics, Pi Digits.
FORMULA
a(n) ~ 10*n if Pi is normal, as generally assumed. - M. F. Hasler, Jul 28 2024
MATHEMATICA
Flatten @ Position[ RealDigits[Pi - 3, 10, 500][[1]], 2] (* Robert G. Wilson v, Mar 07 2011 *)
PROG
(PARI) A037001_upto(N=999, d=2)={localprec(N+20); [i-1|i<-[1..#N=digits(Pi\10^-N)], N[i]==d]} \\ M. F. Hasler, Jul 28 2024
CROSSREFS
Cf. A000796 (decimal expansion (or digits) of Pi).
Cf. A053746 (= a(n) + 1: the same with different offset).
Cf. A037000, A037002, A037003, A037004, A037005, A036974, A037006, A037007, A037008 (similar for digits 1, ..., 9 and 0).
Cf. A035117 (first occurrence of at least n '1's), A050281 (n '2's), A050282, A050283, A050284, A050286, A050287, A048940 (n '9's).
Cf. A096755 (first occurrence of exactly n '1's), A096756, A096757, A096758, A096759, A096760, A096761, A096762, A096763 (exactly n '9's), A050279 (exactly n '0's).
Cf. A121280 = A068987 - 1: position of "123...n" in Pi's decimals.
Cf. A176341: first occurrence of n in Pi's digits.
KEYWORD
nonn,base
AUTHOR
Nicolau C. Saldanha (nicolau(AT)mat.puc-rio.br)
STATUS
approved
Position of the first occurrence of exactly n consecutive '9's in a row in the decimal expansion of Pi.
+10
24
5, 44, 2949, 17988, 19446, 762, 1722776, 36356642, 564665206, 20148132310, 27014073304, 897831316556, 10542036048450, 5758910552709
OFFSET
1,1
LINKS
David G. Andersen, The Pi-Search Page.
Yasumasa Kanada, Statistical Distribution Information, Home Page, Computer Centre, The University of Tokyo.
CROSSREFS
Cf. A000796: Decimal expansion (or digits) of Pi.
First occurrence of n times the same digit: A035117 (n '1's), A050281 (n '2's), A050282, A050283, A050284, A050286, A050287, A048940 (n '9's).
First occurrence of exactly n times the same digit: A096755 (exactly n '1's), A096756, A096757, A096758, A096759, A096760, A096761, A096762, A096763 (exactly n '9's), A050279 (exactly n '0's).
First occurrence of n: A176341; of concatenate(1,...,n): A121280 = A068987 - 1.
KEYWORD
nonn,base,more
AUTHOR
Robert G. Wilson v, Jul 07 2004
EXTENSIONS
a(10)-a(11) from Giovanni Resta, Sep 30 2019
a(12) from Yasumasa Kanada, 2002 and a(13)-a(14) from Shigeru Kondo, 2011, added by Dmitry Petukhov, Dec 27 2019
STATUS
approved
a(n) is the starting position of the first occurrence of a string of exactly n 6's in the decimal expansion of Pi.
+10
22
7, 117, 2440, 21880, 48439, 252499, 8209165, 55616210, 45681781, 386980412, 32104158792, 1221587715177, 81111117323616
OFFSET
1,1
COMMENTS
Differs from A050285 at a(8) > a(9) = A050285(9) = A050285(8). - M. F. Hasler, Apr 13 2019
a(12) > 99*10^9. - Giovanni Resta, Oct 02 2019
a(13) > 22*10^12. - Dmitry Petukhov, Jan 29 2020
a(13)-a(16) > 5*10^13, a(17) = 28642224609576. - Dmitry Petukhov, Oct 30 2021
a(14)-a(16) > 10^14. - Dmitry Petukhov, Sep 19 2022
LINKS
David G. Andersen, The Pi-Search Page.
Timothy Mullican, 50 trillion digits of pi
Eric Weisstein's World of Mathematics, Pi Digits
KEYWORD
nonn,base,more
AUTHOR
Robert G. Wilson v, Jul 07 2004
EXTENSIONS
a(11) from Giovanni Resta, Oct 02 2019
a(12) from Dmitry Petukhov, Jan 14 2020
a(13) from Dmitry Petukhov, Sep 19 2022
STATUS
approved
a(n) is the starting position of the first occurrence of a string of at least n 1's in the decimal expansion of Pi.
+10
21
1, 94, 153, 12700, 32788, 255945, 4657555, 159090113, 812432526, 3961184001, 15647738228, 1041032609981, 3907688331257, 68635742334547
OFFSET
1,2
COMMENTS
Presently identical to A096755, which is the first occurrences of exactly n 1's in the digits of Pi. Will differ as soon as there's some a(n) = a(n+1) and equivalently, A035117(n) > A035117(n+1). - M. F. Hasler, Mar 17 2017
LINKS
David G. Andersen, The Pi-Search Page.
Eric Weisstein's World of Mathematics, Pi Digits.
Yasumasa Kanada Laboratory Home Page, Computer Centre, The University of Tokyo, Statistical Distribution Information
CROSSREFS
Cf. A000796 (decimal expansion (or digits) of Pi).
Cf. A035117 (this), A050281 (n '2's), A050282, A050283, A050284, A050286, A050287, A048940 (n '9's).
Cf. A096755 (exactly n '1's), A096756, A096757, A096758, A096759, A096760, A096761, A096762, A096763 (exactly n '9's), A050279 (exactly n '0's).
Cf. A121280 = A068987 - 1 (position of "123...n" in Pi's decimals).
Cf. A176341 (first occurrence of n in Pi's digits).
KEYWORD
nonn,base,more
AUTHOR
Leonardo Bitran (lbitran(AT)reuna.cl)
EXTENSIONS
More terms from Colin Martin (cbmartin(AT)tpg.com.au), Mar 03 2002
Edited by N. J. A. Sloane at the suggestion of Andrew S. Plewe, May 27 2007
Edited, after re-establishing A096755, by M. F. Hasler, Mar 17 2017
a(11) from Giovanni Resta, Sep 30 2019
a(12) from Yasumasa Kanada Laboratory, 2002 and a(13) from Shigeru Kondo, 2011, added by Dmitry Petukhov, Dec 27 2019
a(14) from Dmitry Petukhov, Sep 19 2022
STATUS
approved
a(n) is the starting position of the first occurrence of a string of at least n '0's in the decimal expansion of Pi.
+10
21
32, 307, 601, 13390, 17534, 1699927, 3794572, 172330850, 2542542102, 8324296435, 371247087572, 1755524129973, 3186699229890, 6381820482331
OFFSET
1,1
COMMENTS
At least up to a(10), also the starting position of the first occurrence of a string of exactly n '0's in the decimal expansion of Pi, cf. A096764. - M. F. Hasler, Mar 19 2017, edited Sep 03 2017
a(15) > 22*10^12. - Dmitry Petukhov, Jan 28 2020
REFERENCES
Shigeru Kondo, calculation of Pi to 12.8 * 10^9 digits, using the program PiFast of Xavier Gourdon
LINKS
David G. Andersen, The Pi-Search Page.
Eric Weisstein's World of Mathematics, Pi Digits
CROSSREFS
See A096764 for another version.
Cf. A000796: Decimal expansion (or digits) of Pi.
First occurrence of exactly n times the same digit: A096755 (exactly n '1's), A096756, A096757, A096758, A096759, A096760, A096761, A096762, A096763 (exactly n '9's), A096764 (exactly n '0's).
First occurrence of n times the same digit: A035117 (n '1's), A050281 (n '2's), A050282, A050283, A050284, A050286, A050287, A048940 (n '9's).
First occurrence of concatenate(1,...,n): A121280 = A068987 - 1.
KEYWORD
nonn,base,more
EXTENSIONS
More terms from Colin B. Martin (martinc(AT)ram.net.au), Nov 25 2001
Edited by N. J. A. Sloane at the suggestion of M. F. Hasler, Aug 24 2007
Edited by M. F. Hasler, Mar 19 2017
Definition modified by N. J. A. Sloane, Sep 03 2017
a(11)-a(14) added by Dmitry Petukhov, Jan 12 2020
STATUS
approved
Index of first occurrence of just n consecutive fives in a row in the decimal expansion of Pi.
+10
21
4, 130, 177, 33172, 24466, 244453, 3517236, 168743355, 5050944965, 7644991298, 157675736216, 1618922020656, 9593946215340, 7604259624808
OFFSET
1,1
COMMENTS
Differs from A050284 as soon as a(4) > a(5) = A050284(4) = A050284(5). - M. F. Hasler, Apr 13 2019
a(11) > 99*10^9. - Giovanni Resta, Oct 02 2019
a(15) > 22*10^12. - Dmitry Petukhov, Jan 29 2020
KEYWORD
nonn,base,more
AUTHOR
Robert G. Wilson v, Jul 07 2004
EXTENSIONS
Typo in a(10) corrected by Giovanni Resta, Oct 02 2019
a(11)-a(14) added by Dmitry Petukhov, Jan 12 2020
STATUS
approved
Position of first occurrence of exactly n consecutive sevens in a row in the decimal expansion of Pi.
+10
21
13, 559, 4575, 1589, 162248, 399579, 3346228, 82144203, 24658601, 22869046249, 165431035708, 368299898266, 10541103245815, 14793486898235, 46970519777308
OFFSET
1,1
COMMENTS
Differs from A050286 from a(3) > a(4) on. - M. F. Hasler, Mar 18 2017
a(11) > 99*10^9. - Giovanni Resta, Oct 02 2019
a(15) > 22*10^12. - Dmitry Petukhov, Jan 27 2020
a(16) > 50*10^12. - Dmitry Petukhov, Oct 30 2021
CROSSREFS
First occurrence of n times the same digit: A035117 (n '1's), A050281 (n '2's), A050282, A050283, A050284, A050286, A050287, A048940 (n '9's).
First occurrence of exactly n times the same digit: A096755 (exactly n '1's), A096756, A096757, A096758, A096759, A096760, A096761, A096762, A096763 (exactly n '9's), A050279 (exactly n '0's).
First occurrence of n: A176341; of concatenate(1,...,n): A121280 = A068987 - 1.
Cf. A000796 (decimal expansion (or digits) of Pi).
KEYWORD
nonn,base,more
AUTHOR
Robert G. Wilson v, Jul 07 2004
EXTENSIONS
Edited by M. F. Hasler, Mar 19 2017
a(10) from Giovanni Resta, Oct 02 2019
a(11)-a(13) added by Dmitry Petukhov, Jan 13 2020
a(14) from Dmitry Petukhov, Jan 27 2020
a(15) from Dmitry Petukhov, Oct 30 2021
STATUS
approved
Starting position of the first occurrence of a string of at least n '9's in the decimal expansion of Pi.
+10
20
5, 44, 762, 762, 762, 762, 1722776, 36356642, 564665206, 20148132310, 27014073304, 897831316556, 5758910552709, 5758910552709
OFFSET
1,1
COMMENTS
a(10) > 11*10^9 - 1. - Eric W. Weisstein, Jul 20 2013
a(15) > 22*10^12. - Dmitry Petukhov, Jan 29 2020
Pi digits 3,1,4,... are indexed 0,1,2,... Note that this is different from other sequences such as A049522, A084073 which use indices 1,2,3,... For example, the position of the curious accumulation of six 9s is called 762 here; the same position is called 763 in A049522, A084073. - Jeppe Stig Nielsen, Aug 21 2017
LINKS
David G. Andersen, The Pi-Search Page. (Yields, as of today, an incorrect result of 66780105 for the first occurrence of eight "9"s. - M. F. Hasler, Mar 19 2017)
Yasumasa Kanada Laboratory Home Page, Computer Centre, The University of Tokyo, Statistical Distribution Information
Eric Weisstein's World of Mathematics, Feynman Point
Eric Weisstein's World of Mathematics, Pi Digits
MATHEMATICA
Module[{m, nn = 7}, m = First@ RealDigits@ N[Pi, 10^nn]; Array[ SequencePosition[m, ConstantArray[9, #]][[1, 1]] - 1 &, nn]] (* Michael De Vlieger, Mar 20 2017 *)
CROSSREFS
Cf. A000796: Decimal expansion (or digits) of Pi.
First occurrence of n times the same digit: A035117 (n '1's), A050281 (n '2's), A050282, A050283, A050284, A050286, A050287, A048940 (n '9's).
First occurrence of exactly n times the same digit: A096755 (exactly n '1's), A096756, A096757, A096758, A096759, A096760, A096761, A096762, A096763 (exactly n '9's), A050279 (exactly n '0's).
First occurrence of n: A176341; of concatenate(1,...,n): A121280 = A068987 - 1.
KEYWORD
nonn,base,more
EXTENSIONS
More terms from Colin Martin (cbmartin(AT)tpg.com.au), Mar 03 2002
Edited by M. F. Hasler, Mar 19 2017
a(10)-a(11) from Giovanni Resta, Sep 30 2019
a(12) from Yasumasa Kanada Laboratory, 2002 and a(13)-a(14) from Shigeru Kondo, 2011 added by Dmitry Petukhov, Dec 23 2019
STATUS
approved
Index of first occurrence of exactly n consecutive twos in a row in the decimal expansion of Pi.
+10
20
6, 135, 1735, 4902, 65260, 963024, 82599811, 175820910, 1270311937, 20717271655, 225023890967, 1479132847647, 5547233660249
OFFSET
1,1
COMMENTS
Presently identical to A050281, but it can be expected that the two will eventually differ, namely, as soon as a(n) > a(n+1) and A050281(n) = A050281(n+1).
a(10) > 2*10^9, according to the SubIdiom.com search engine. - M. F. Hasler, Apr 13 2019
a(11) > 99*10^9. - Giovanni Resta, Oct 02 2019
a(14) > 22*10^12. - Dmitry Petukhov, Jan 28 2020
EXAMPLE
Pi = 3.1415926... has a "run" of exactly one '2' in the 6th place after the decimal point, therefore a(1) = 6.
KEYWORD
nonn,base,more
AUTHOR
Robert G. Wilson v, Jul 07 2004
EXTENSIONS
a(10) from Giovanni Resta, Oct 02 2019
a(11)-a(13) from Dmitry Petukhov, Jan 14 2020
STATUS
approved
Index of first occurrence of exactly n consecutive threes in a row in the decimal expansion of Pi.
+10
20
9, 24, 1698, 66846, 28467, 1129019, 710100, 36488176, 2011485307, 4663739959, 60422218263, 1379574176590, 26258139334603
OFFSET
1,1
COMMENTS
Differs from A050282 as soon as a(4) > a(5), while A050282(4) = A050282(5) = a(5). - M. F. Hasler, Apr 13 2019
a(12) > 99*10^9. - Giovanni Resta, Oct 02 2019
a(13) > 22*10^12. - Dmitry Petukhov, Jan 26 2020
a(14) > 50*10^12. - Dmitry Petukhov, Oct 28 2021
CROSSREFS
Cf. A050282 (same for at least three 3s); A050279, A035117, A096756, A096758, A096759, A096760, A096761, A096762, A096763 (analog for digits 0, 1, 2, 4, ...).
KEYWORD
nonn,base,more
AUTHOR
Robert G. Wilson v, Jul 07 2004
EXTENSIONS
a(11) from Giovanni Resta, Oct 02 2019
a(12) from Dmitry Petukhov, Jan 26 2020
a(13) from Dmitry Petukhov, Oct 28 2021
STATUS
approved

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