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A007320 Number of steps needed for juggler sequence (A094683) started at n to reach 1.
(Formerly M4047)
+0
18
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 (list; graph; listen)
OFFSET

1,3

COMMENT

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

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

C. Pickover, Computers and the Imagination, St. Martin's Press, NY, 1991, p. 232.

LINKS

Eric Weisstein's World of Mathematics, Juggler Sequence

H. J. Smith, Juggler Sequence

EXAMPLE

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.

MAPLE

f:=proc(n) if n mod 2 = 0 then RETURN(floor(sqrt(n))) else RETURN(floor(n^(3/2))); fi; end; h:=proc(n) local i, j, t1; i:=0; j:=100; t1:=n; while t1 <> 1 and i < j do t1:=f(t1); i:=i+1; od: RETURN(min(i, j)); end;

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}] (from Robert G. Wilson v Jun 10 2004)

CROSSREFS

Cf. A007321, A094683, A094698, A094679, A093685, A094716.

Sequence in context: A058160 A033939 A021020 this_sequence A007321 A062828 A124457

Adjacent sequences: A007317 A007318 A007319 this_sequence A007321 A007322 A007323

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Robert G. Wilson v (rgwv(AT)rgwv.com), Mira Bernstein (mira(AT)math.berkeley.edu)

EXTENSIONS

Corrected and extended by Jason Earls, Jun 09 2004

page 1

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Last modified December 4 15:11 EST 2009. Contains 170347 sequences.


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