A039502 - OEIS

A039502

Iterations of "n->n/2 if n even, n->3n-1 if n odd" (A001281) starting at these numbers reach 17.

17, 21, 23, 25, 31, 33, 34, 37, 41, 42, 45, 46, 49, 50, 55, 61, 62, 66, 67, 68, 73, 74, 82, 83, 84, 90, 91, 92, 98, 99, 100, 109, 110, 111, 117, 122, 123, 124, 131, 132, 134, 136, 146, 147, 148, 153, 163, 164, 165, 166, 168, 175, 179, 180, 182, 184, 185, 195, 196

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..59.

MATHEMATICA

colln[n_]:= NestWhile[If[EvenQ[#], #/2, 3#-1] &, n, FreeQ[{1, 5, 17}, #] &]; Select[Range[196], colln[#] == 17 &] (* Jayanta Basu, Jun 06 2013 *)

CROSSREFS

Cf. A037084, A039500-A039505.

Sequence in context: A045020 A069961 A140146 * A039505 A166875 A282109

Adjacent sequences: A039499 A039500 A039501 * A039503 A039504 A039505

KEYWORD

nonn,easy

AUTHOR

Christian G. Bower, Feb 15 1999

STATUS

approved