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 1-9 of 9 results.

A094683 Juggler sequence: if n mod 2 = 0 then floor(sqrt(n)) else floor(n^(3/2)).

Original entry on oeis.org

0, 1, 1, 5, 2, 11, 2, 18, 2, 27, 3, 36, 3, 46, 3, 58, 4, 70, 4, 82, 4, 96, 4, 110, 4, 125, 5, 140, 5, 156, 5, 172, 5, 189, 5, 207, 6, 225, 6, 243, 6, 262, 6, 281, 6, 301, 6, 322, 6, 343, 7, 364, 7, 385, 7, 407, 7, 430, 7, 453, 7, 476, 7, 500, 8, 524, 8, 548, 8, 573, 8, 598, 8, 623, 8, 649
Offset: 0

Views

Author

N. J. A. Sloane, Jun 09 2004

Keywords

Comments

Interspersion of A000093 and A000196. - Michel Marcus, Nov 11 2013

References

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

Crossrefs

Programs

  • Maple
    A094683 :=proc(n) if n mod 2 = 0 then RETURN(floor(sqrt(n))) else RETURN(floor(n^(3/2))); end if; end proc;
  • Mathematica
    Table[If[EvenQ[n], Floor[Sqrt[n]], Floor[n^(3/2)]], {n, 0, 100}] (* Indranil Ghosh, Apr 07 2017 *)
  • PARI
    a(n) = if(n%2,sqrtint(n^3), sqrtint(n)); \\ Indranil Ghosh, Apr 08 2017
    
  • Python
    import math
    from sympy import sqrt
    def a(n): return int(math.floor(sqrt(n))) if n%2 == 0 else int(math.floor(n**(3/2)))
    print([a(n) for n in range(51)]) # Indranil Ghosh, Apr 08 2017
    
  • Python
    from math import isqrt
    def A094683(n): return isqrt(n**3 if n % 2 else n) # Chai Wah Wu, Feb 18 2022

A007320 Number of steps needed for juggler sequence (A094683) started at n to reach 1.

Original entry on oeis.org

0, 1, 6, 2, 5, 2, 4, 2, 7, 7, 4, 7, 4, 7, 6, 3, 4, 3, 9, 3, 9, 3, 9, 3, 11, 6, 6, 6, 9, 6, 6, 6, 8, 6, 8, 3, 17, 3, 14, 3, 5, 3, 6, 3, 6, 3, 6, 3, 11, 5, 11, 5, 11, 5, 11, 5, 5, 5, 11, 5, 11, 5, 5, 3, 5, 3, 11, 3, 14, 3, 5, 3, 8, 3, 8, 3, 19, 3, 8, 3, 10, 8, 8, 8, 11, 8, 10, 8, 11, 8, 11, 8, 11, 8, 8, 8, 11
Offset: 1

Views

Author

Keywords

Comments

It is not known if every starting value eventually reaches 1.

Examples

			The trajectory of 1 is 3, 5, 11, 36, 6, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ... so a(3) = 6.
		

References

  • C. Pickover, Computers and the Imagination, St. Martin's Press, NY, 1991, p. 232.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Programs

  • Maple
    A007320 := proc(n)
        local a,ntrack;
        a := 0 ;
        ntrack := n ;
        while ntrack > 1 do
            ntrack := A094683(ntrack) ;
            a := a+1 ;
        end do:
        return a;
    end proc: # R. J. Mathar, Apr 19 2013
  • Mathematica
    js[n_] := If[ EvenQ[n], Floor[ Sqrt[n]], Floor[ Sqrt[n^3]]]; f[n_] := Length[ NestWhileList[js, n, # != 1 &]] - 1; Table[ f[n], {n, 99}] (* Robert G. Wilson v, Jun 10 2004 *)

Extensions

Corrected and extended by Jason Earls, Jun 09 2004

A095396 Modified juggler map: for even numbers: a(n) = floor(n^(2/3)) and for odd n: a(n) = floor(n^(3/2)) = floor(sqrt(n^3)).

Original entry on oeis.org

1, 1, 5, 2, 11, 3, 18, 4, 27, 4, 36, 5, 46, 5, 58, 6, 70, 6, 82, 7, 96, 7, 110, 8, 125, 8, 140, 9, 156, 9, 172, 10, 189, 10, 207, 10, 225, 11, 243, 11, 262, 12, 281, 12, 301, 12, 322, 13, 343, 13, 364, 13, 385, 14, 407, 14, 430, 14, 453, 15, 476, 15, 500, 16, 524, 16, 548, 16
Offset: 1

Views

Author

Labos Elemer, Jun 18 2004

Keywords

Comments

Parallel to A094683: values for odd arguments are same, for even not necessarily so.

Crossrefs

Programs

  • Mathematica
    d[x_]:=d[x]=(1-Mod[x, 2])*Floor[N[x^(2/3), 50]] +Mod[x, 2]*Floor[N[x^(3/2), 50]];d[1]=1; Table[d[w], {w, 1, 150}]
    Table[If[EvenQ[n],Floor[n^(2/3)],Floor[n^(3/2)]],{n,70}] (* Harvey P. Dale, Dec 28 2018 *)
  • Scheme
    (define (A095396 n) (if (even? n) (A048766 (* n n)) (A000196 (* n n n)))) ;; Antti Karttunen, May 28 2017

Formula

For even n: a(n) = A048766(n^2), for odd n: a(n) = A000196(n^3). - Antti Karttunen, May 28 2017

Extensions

Name simplified by Antti Karttunen, May 28 2017

A095397 Modified juggler map: see A095396. Largest value in trajectory of started n under the juggler map of A095396.

Original entry on oeis.org

1, 2, 36, 4, 36, 36, 36, 8, 140, 10, 36, 36, 46, 36, 58, 36, 70, 36, 82, 36, 96, 36, 110, 24, 52214, 26, 140, 140, 156, 140, 172, 32, 2598, 34, 2978, 36, 86818724, 38, 233046, 40, 262, 42, 4710, 44, 5222, 46, 322, 48, 6352, 50, 364, 52, 7554, 54, 8210, 56, 430, 58
Offset: 1

Views

Author

Labos Elemer, Jun 18 2004

Keywords

Comments

Parallel to A094716.

Examples

			n=37: the trajectory is {37, 225, 3375, 196069, 86818724, 196068, 3374, 224, 36, 10, 4, 2, 1}, the peak is a[37]=86818724
		

Crossrefs

Programs

  • Mathematica
    d[x_]:=d[x]=(1-Mod[x, 2])*Floor[N[x^(2/3), 50]] +Mod[x, 2]*Floor[N[x^(3/2), 50]];d[1]=1; fd[x_]:=Delete[FixedPointList[d, x], -1] Table[Max[fd[w]], {w, 1, m}]

A095398 Number of steps required to reach 1 for iterated modified juggler map of A095396.

Original entry on oeis.org

0, 1, 7, 2, 6, 8, 10, 3, 7, 3, 5, 7, 9, 7, 9, 9, 11, 9, 11, 11, 13, 11, 13, 4, 10, 4, 6, 8, 10, 8, 10, 4, 8, 4, 8, 4, 12, 6, 12, 6, 8, 8, 12, 8, 12, 8, 10, 10, 14, 10, 12, 10, 14, 8, 12, 8, 10, 8, 14, 10, 12, 10, 12, 10, 12, 10, 12, 10, 14, 10, 12, 12, 16, 12, 18, 12, 18, 10, 12, 10, 16
Offset: 1

Views

Author

Labos Elemer, Jun 18 2004

Keywords

Comments

Parallel to A007320.

Examples

			n=37: the trajectory is {37, 225, 3375, 196069, 86818724, 196068, 3374, 224, 36, 10, 4, 2, 1}, number of required steps is a[37]=13-1=12.
		

Crossrefs

Programs

  • Mathematica
    d[x_]:=d[x]=(1-Mod[x, 2])*Floor[N[x^(2/3), 50]] +Mod[x, 2]*Floor[N[x^(3/2), 50]];d[1]=1; fd[x_]:=Delete[FixedPointList[d, x], -1] Table[Max[fd[w]], {w, 1, m}]
    Table[Length[NestWhileList[If[EvenQ[#],Floor[#^(2/3)],Floor[#^(3/2)]]&, n, #!=1&]]-1,{n,90}] (* Harvey P. Dale, Dec 28 2018 *)

A218335 Even numbers n such that the largest value in trajectory of n under the juggler map of A094683 is greater than n.

Original entry on oeis.org

10, 12, 14, 26, 28, 30, 32, 34, 82, 84, 86, 88, 90, 92, 94, 96, 98, 626, 628, 630, 632, 634, 636, 638, 640, 642, 644, 646, 648, 650, 652, 654, 656, 658, 660, 662, 664, 666, 668, 670, 672, 674, 1090, 1092, 1094, 1096, 1098, 1100, 1102, 1104, 1106, 1108, 1110
Offset: 1

Views

Author

Arkadiusz Wesolowski, Oct 26 2012

Keywords

Crossrefs

Programs

  • Mathematica
    lst = {}; Do[n = a; While[True, If[EvenQ[a], a = Floor[a^(1/2)]; If[a == 1, Break[]], a = Floor[a^(3/2)]; If[a > n, AppendTo[lst, n]; Break[]]]], {a, 2, 1110, 2}]; lst

Formula

A number n is in the sequence if and only if n is even and A094716(n) > n.

A095399 Modified juggler modified further: a[n]=(1-Mod[n,2])*Floor[n^(3/4)]+Mod[n,2]*Floor[n^(4/3)]; original exponents {1/2,3/2} are replaced with {3/4,4/3}.

Original entry on oeis.org

1, 1, 4, 2, 8, 3, 13, 4, 18, 5, 24, 6, 30, 7, 36, 8, 43, 8, 50, 9, 57, 10, 65, 10, 73, 11, 81, 12, 89, 12, 97, 13, 105, 14, 114, 14, 123, 15, 132, 15, 141, 16, 150, 17, 160, 17, 169, 18, 179, 18, 189, 19, 199, 19, 209, 20, 219, 21, 229, 21, 240, 22, 250, 22, 261, 23, 272, 23
Offset: 1

Views

Author

Labos Elemer, Jun 18 2004

Keywords

Crossrefs

Programs

  • Mathematica
    e[x_]:=e[x]=(1-Mod[x, 2])*Floor[N[x^(3/4), 50]] +Mod[x, 2]*Floor[N[x^(4/3), 50]];e[1]=1; Table[e[w], {w, 1, 150}]

A095400 Largest value in trajectory when the following modified juggler map is iterated: a[n]=(1-Mod[n, 2])*Floor[n^(3/4)]+Mod[n, 2]*Floor[n^(4/3)]; original exponents {1/2, 3/2} are replaced with {3/4, 4/3}.

Original entry on oeis.org

1, 2, 4, 4, 8, 6, 30, 8, 18, 10, 24, 12, 30, 30, 36, 16, 150, 18, 50, 20, 1320, 22, 43366048, 24, 26092, 26, 350, 28, 41678, 30, 234421146, 32, 2438232, 34, 114, 36, 5184, 38, 132, 40, 124026, 42, 150, 150, 160, 150, 934, 48, 1008, 50, 1084, 52, 12202, 54, 1240, 56
Offset: 1

Views

Author

Labos Elemer, Jun 18 2004

Keywords

Examples

			n=101: the trajectory is {101, 470, 100, 31, 97, 445, 3397, 51065, 1894513, 234421146, 1894512, 51064, 3396, 444, 96, 30, 12, 6, 3, 4, 2, 1}, peak=a[101]=234421146.
		

Crossrefs

Programs

  • Mathematica
    e[x_]:=e[x]=(1-Mod[x, 2])*Floor[N[x^(3/4), 50]] +Mod[x, 2]*Floor[N[x^(4/3), 50]];e[1]=1; fe[x_]:=Delete[FixedPointList[e, x], -1]; Table[Max[fe[w]], {w, 1, 150}]

A095401 number of steps required to reach 1 if the following modified juggler map is iterated: a[n]=(1-Mod[n, 2])*Floor[n^(3/4)]+Mod[n, 2]*Floor[n^(4/3)]; original exponents {1/2, 3/2} are replaced with {3/4, 4/3}.

Original entry on oeis.org

0, 1, 3, 2, 4, 4, 8, 3, 5, 5, 7, 5, 7, 9, 11, 4, 8, 4, 6, 6, 12, 6, 18, 6, 14, 8, 12, 6, 14, 6, 18, 8, 18, 10, 12, 10, 16, 12, 14, 12, 20, 5, 7, 9, 11, 9, 13, 5, 9, 5, 9, 7, 13, 7, 11, 7, 11, 13, 19, 13, 15, 7, 9, 7, 17, 19, 21, 19, 23, 7, 11, 7, 13, 15, 17, 15, 19, 9, 11, 9, 11, 13, 15, 13, 19
Offset: 1

Views

Author

Labos Elemer, Jun 18 2004

Keywords

Examples

			n=101: the trajectory is {101, 470, 100, 31, 97, 445, 3397, 51065, 1894513, 234421146, 1894512, 51064, 3396, 444, 96, 30, 12, 6, 3, 4, 2, 1}, number of required steps is a[101]=22-1=21.
		

Crossrefs

Programs

  • Mathematica
    e[x_]:=e[x]=(1-Mod[x, 2])*Floor[N[x^(3/4), 50]] +Mod[x, 2]*Floor[N[x^(4/3), 50]];e[1]=1; fe[x_]:=Delete[FixedPointList[e, x], -1]; Table[ -1+Length[fe[w]], {w, 1, 150}]
Showing 1-9 of 9 results.