

A003124


One of the basic cycles in the x>3x1 (x odd) or x/2 (x even) problem.


3



17, 50, 25, 74, 37, 110, 55, 164, 82, 41, 122, 61, 182, 91, 272, 136, 68, 34, 17, 50, 25, 74, 37, 110, 55, 164, 82, 41, 122, 61, 182, 91, 272, 136, 68, 34, 17, 50, 25, 74, 37, 110, 55, 164, 82, 41, 122, 61, 182, 91, 272, 136, 68, 34
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OFFSET

0,1


REFERENCES

Richard K. Guy, Unsolved Problems in Number Theory, E16.
H.O. Peitgen et al., Chaos and Fractals, Springer, p. 33.


LINKS

Table of n, a(n) for n=0..53.


EXAMPLE

17 is odd, so the next term is 3 * 17  1 = 50.
50 is even, so the next term is 50/2 = 25.


MATHEMATICA

Abs[NestList[If[EvenQ[#], #/2, 3# + 1]&, 17, 100]] (* Alonso del Arte, May 19 2015 *)


PROG

(PARI) a=34; A003124=vector(100, i, a=if(bittest(a, 0), 3*a1, a/2)) \\ M. F. Hasler, Aug 29 2015
(PARI) A003124(n, a=17)={for(i=1, n%17, a=if(bittest(a, 0), 3*a1, a\2)); a} \\ M. F. Hasler, Aug 29 2015


CROSSREFS

Sequence in context: A146461 A098329 A160076 * A005570 A195037 A214660
Adjacent sequences: A003121 A003122 A003123 * A003125 A003126 A003127


KEYWORD

nonn,easy


AUTHOR

N. J. A. Sloane.


STATUS

approved



