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.

User: Vikram Prasad

Vikram Prasad's wiki page.

Vikram Prasad has authored 3 sequences.

A381246 Largest value in trajectory of n under the juggler map of A380891.

Original entry on oeis.org

1, 2, 4, 4, 8, 6, 30, 8, 18, 10, 24, 12, 30, 14, 36, 16, 150, 18, 50, 20, 1320, 22, 43366048, 24, 41678, 26, 350, 28, 41678, 30, 234421146, 32, 2438232, 34, 114, 36, 5184, 38, 132, 40, 124026, 42, 150, 44, 160, 46, 934, 48, 1008, 50, 1084, 52, 43366048, 54, 1240
Offset: 1

Author

James C. McMahon and Vikram Prasad, Apr 17 2025

Keywords

Comments

A380891(x) map is If x mod 2 = 0 then a(x) = floor(x^(1/3)) else a(x) = floor(x^(4/3)).

Crossrefs

Programs

  • Mathematica
    fj[n_]:=If[Mod[n,2]==0,Floor[Surd[n,3]],Floor[n^(4/3)]];a381246[n_]:=Max[Delete[FixedPointList[fj, n], -1]];Array[a381246,55]
  • Python
    import sys
    import gmpy2
    sys.set_int_max_str_digits(0)
    def floorJuggler(n):
        a=n
        max=n
        while a > 1:
            b=0
            if a%2 == 0:
                b1=gmpy2.iroot(a,3)
                b=b1[0]
            else:
                b1=gmpy2.iroot(a**4,3)
                b=b1[0]
            a=b
            if a > max:
                max = a
        return max
    maxcount=0
    for i in range (1, 100):
        print (i, floorJuggler(i))

A383135 a(n) = number of iterations that n requires to reach 1 under the x -> A380891(x) map, or -1 if it never does.

Original entry on oeis.org

0, 1, 2, 1, 3, 1, 5, 2, 3, 2, 3, 2, 4, 2, 4, 2, 6, 2, 4, 2, 6, 2, 13, 2, 13, 2, 8, 3, 8, 3, 10, 3, 10, 3, 3, 3, 10, 3, 5, 3, 10, 3, 5, 3, 5, 3, 6, 3, 5, 3, 5, 3, 17, 3, 5, 3, 5, 3, 17, 3, 3, 3, 3, 2, 12, 2, 3, 2, 5, 2, 5, 2, 12, 2, 3, 2, 7, 2, 3, 2, 7, 2, 7, 2
Offset: 1

Author

James C. McMahon and Vikram Prasad, Apr 17 2025

Keywords

Comments

A380891(x) map is If x mod 2 = 0 then a(x) = floor(x^(1/3)) else a(x) = floor(x^(4/3)).
The map x -> A380891(x) is conjectured to eventually reach 1 for all starting x > 0. Tested for x <= 7892481.

Crossrefs

Programs

  • Mathematica
    fj[n_]:=If[Mod[n,2]==0,Floor[Surd[n,3]],Floor[n^(4/3)]];a383135[n_]:= Length[ NestWhileList[fj, n, # != 1 &]] - 1; Array[ a383135, 84]
  • Python
    import sys
    import gmpy2
    sys.set_int_max_str_digits(0)
    def floorJuggler(n) :
        a=n
        count=0
        while (a > 1) :
            b=0
            if (a%2 == 0) :
                b1=gmpy2.iroot(a,3)
                b=b1[0]
                count=count+1
            else :
                b1=gmpy2.iroot(a**4,3)
                b=b1[0]
                count=count+1
            a=b
        return count
    for i in range (1, 100) :
        print (i, floorJuggler(i))

A380891 If n mod 2 = 0 then a(n) = floor(n^(1/3)) else a(n) = floor(n^(4/3)).

Original entry on oeis.org

0, 1, 1, 4, 1, 8, 1, 13, 2, 18, 2, 24, 2, 30, 2, 36, 2, 43, 2, 50, 2, 57, 2, 65, 2, 73, 2, 81, 3, 89, 3, 97, 3, 105, 3, 114, 3, 123, 3, 132, 3, 141, 3, 150, 3, 160, 3, 169, 3, 179, 3, 189, 3, 199, 3, 209, 3, 219, 3, 229, 3, 240, 3, 250, 4, 261, 4, 272
Offset: 0

Author

Vikram Prasad, Feb 08 2025

Keywords

Crossrefs

Interspersion of A048766 and A129011.

Programs

  • Mathematica
    a[n_]:=If[Mod[n,2]==0,Floor[n^(1/3)],Floor[n^(4/3)]]; (* James C. McMahon, Apr 11 2025 *)
  • Python
    import gmpy2
    def a(n): return int(gmpy2.iroot(n**4 if n&1 else n, 3)[0])