cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-7 of 7 results.

A094679 n sets a new record for number of iterations to reach 1 in the juggler sequence problem.

Original entry on oeis.org

1, 2, 3, 9, 19, 25, 37, 77, 163, 193, 1119, 1155, 4065, 4229, 4649, 7847, 13325, 34175, 59739, 78901, 636731, 1122603, 1301535, 2263913, 5947165, 72511173, 78641579, 125121851, 198424189, 4488817391
Offset: 1

Views

Author

Jason Earls, Jun 09 2004

Keywords

Comments

Where records occur in A007320.
The Juggler sequence: begin with x and if x is even, [sqrt(x)] -> x and if x is odd, [sqrt(x^3)] -> x and repeat until x = 1, count the iterations. - Robert G. Wilson v, Jun 14 2004
78901 reaches a maximum of 4064983429...(skip the next 371727 digits)...2140697134 during its trip to 1. - Robert G. Wilson v, Jun 14 2004
I postulate that 2 is the only even number in this sequence. - Harry J. Smith, Aug 15 2008
a(30) > 1.6*10^9. - Giovanni Resta, Apr 08 2017

Examples

			78901 takes 258 iterations to reach 1; see A094698 for the others.
		

Crossrefs

Programs

  • Mathematica
    $MaxPrecision = 250000000; js[n_] := If[ EvenQ[ n], Floor[ Sqrt[n]], Floor[ Sqrt[n^3]]]; f[n_] := Block[{c = 1, k = n}, While[k = js[k]; k != 1, c++ ]; c]; a = {0}; Do[ b = f[n]; If[b > a[[ -1]], AppendTo[a, b]], {n, 3053595}]; a (* Robert G. Wilson v *)

Extensions

More terms from Robert G. Wilson v, Jun 14 2004
a(25) = 5947165 from Eric W. Weisstein, Jan 25 2006
a(26)-a(27) from Robert G. Wilson v, Jun 15 2014
a(28)-a(29) from Giovanni Resta, Apr 08 2017
a(30) from Ethan Slota, Apr 15 2025

A094698 Number of steps where the Juggler sequence reaches a new record.

Original entry on oeis.org

0, 1, 6, 7, 9, 11, 17, 19, 43, 73, 75, 80, 88, 96, 107, 131, 166, 193, 201, 258, 263, 268, 271, 298, 335, 340, 443, 479, 484, 527
Offset: 1

Views

Author

N. J. A. Sloane, Jun 09 2004

Keywords

Comments

Records in A007320.
The Juggler sequence: begin with x; if x is even, floor(sqrt(x)) -> x; if x is odd, floor(sqrt(x^3)) -> x; repeat until x = 1, count the iterations.

Crossrefs

Programs

  • Mathematica
    $MaxPrecision = 250000000; js[n_] := If[ EvenQ[ n], Floor[ Sqrt[n]], Floor[ Sqrt[n^3]]]; f[n_] := Block[{c = 1, k = n}, While[k = js[k]; k != 1, c++ ]; c]; a = {0}; Do[ b = f[n]; If[b > a[[ -1]], AppendTo[a, b]; Print[n]], {n, 3053595}] (* Robert G. Wilson v, Jun 14 2004 *)

Extensions

More terms from Robert G. Wilson v, Jun 14 2004
a(25) = 335 from Eric W. Weisstein, Jan 25 2006
Edited by N. J. A. Sloane, Sep 16 2008 at the suggestion of Tim Nikkel
a(26)-a(29) from Giovanni Resta, Apr 08 2017
a(30) from Ethan Slota, Apr 15 2025

A143745 The next largest juggler number.

Original entry on oeis.org

1, 2, 36, 140, 52214, 24906114455136, 202924588924125339424550328
Offset: 1

Views

Author

Harry J. Smith, Oct 08 2008

Keywords

Comments

The juggler sequence: begin with a starting value x and if x is even, x <- floor(sqrt(x)) and if x is odd, x <- floor(sqrt(x^3)) and repeat until x = 1, save the starting value, max x and the number of steps needed to reach it.
I have a b-file for this sequence for n=1,...,19 (all known values), but some a(n) values are much larger than 1000 digits.

Examples

			24906114455136 is in the sequence because starting at 37 the juggler sequences maxes out at 24906114455136, a 14-digit number, after 8 steps. This is the largest juggler number found for starting values less than or equal to 37.
		

References

  • C. Pickover, Computers and the Imagination, St. Martin's Press, NY, 1991, p. 233.

Crossrefs

A143742 Starting values that produce a larger juggler number than smaller starting values.

Original entry on oeis.org

1, 2, 3, 9, 25, 37, 113, 173, 193, 2183, 11229, 15065, 15845, 30817, 48443, 275485, 1267909, 2264915, 5812827, 7110201
Offset: 1

Views

Author

Harry J. Smith, Oct 06 2008

Keywords

Comments

The juggler sequence: begin with a starting value x and if x is even, x -> [sqrt(x)] and if x is odd, x -> [sqrt(x^3)] and repeat until x = 1, save the starting value, max x and the number of steps needed to reach it.

Examples

			37 is in the sequence because starting at 37 the juggler sequences maxes out at 24906114455136, a 14-digit number, after 8 steps. This is the largest juggler number found for starting values less than or equal to 37.
		

References

  • C. Pickover, Computers and the Imagination, St. Martin's Press, NY, 1991, p. 233.

Crossrefs

Programs

  • Mathematica
    DeleteDuplicates[Table[{n,Max[NestWhileList[If[EvenQ[#],Floor[Sqrt[#]],Floor[Sqrt[#^3]]]&,n,#!=1&]]},{n,50000}],GreaterEqual [#1[[2]],#2[[2]]]&][[;;,1]] (* The program generates the first 15 terms of the sequence. *) (* Harvey P. Dale, Dec 21 2024 *)

Extensions

Comment clarified by Harvey P. Dale, Dec 21 2024

A143743 The number of digits in the next largest juggler number.

Original entry on oeis.org

1, 1, 2, 3, 5, 14, 27, 82, 271, 5929, 8201, 11723, 23889, 45391, 972463, 1909410, 1952329, 2855584, 7996276
Offset: 1

Views

Author

Harry J. Smith, Oct 08 2008

Keywords

Comments

The juggler sequence: begin with a starting value x and if x is even, x <- [sqrt(x)] and if x is odd, x <- [sqrt(x^3)] and repeat until x = 1, save the starting value, max x and the number of steps needed to reach it.

Examples

			14 is in the sequence because starting at 37 the juggler sequence maxes out at 24906114455136, a 14-digit number, after 8 steps. This is the largest juggler number found for starting values less than or equal to 37.
		

References

  • C. Pickover, Computers and the Imagination, St. Martin's Press, NY, 1991, p. 233.

Crossrefs

A143744 The number of steps needed to generate the next largest juggler number.

Original entry on oeis.org

0, 0, 3, 2, 3, 8, 9, 17, 47, 32, 54, 25, 43, 39, 60, 148, 99, 89, 67
Offset: 1

Views

Author

Harry J. Smith, Oct 08 2008

Keywords

Comments

The juggler sequence: begin with a starting value x and if x is even, x <- [sqrt(x)] and if x is odd, x <- [sqrt(x^3)] and repeat until x = 1, save the starting value, max x and the number of steps needed to reach it.

Examples

			8 is in the sequence because starting at 37 the juggler sequences maxes out at 24906114455136, a 14-digit number, after 8 steps. This is the largest juggler number found for starting values less than or equal to 37.
		

References

  • C. Pickover, Computers and the Imagination, St. Martin's Press, NY, 1991, p. 233.

Crossrefs

A284987 Juggler sequence starting at 37.

Original entry on oeis.org

37, 225, 3375, 196069, 86818724, 9317, 899319, 852846071, 24906114455136, 4990602, 2233, 105519, 34276462, 5854, 76, 8, 2, 1
Offset: 0

Views

Author

Matt Westwood, Apr 07 2017

Keywords

Comments

Many sources state that the Juggler sequence on 37 is, for example, "the first tall peak in its graph", and "the high water number of steps are" and so on, without specifically giving the actual sequence. As this specific instance is cited in various places as a specific instance, if not a special case, it seems worthy to document it here explicitly.

References

  • David Wells, The Penguin Dictionary of Curious and Interesting Numbers, Revised Edition, Penguin Books, 1997, page 99.

Crossrefs

Programs

  • PARI
    Juggler(n)={my(L=List([n])); while(n<>1, n=sqrtint(n^(2-(-1)^n)); listput(L,n)); Vec(L)}
    { Juggler(37) } \\ Andrew Howroyd, Apr 27 2020

Formula

a(0) = 37, a(n) = floor(sqrt(a(n-1))): n even, a(n) = floor((sqrt(a(n-1)))^3): n odd.
Showing 1-7 of 7 results.