A039501 Iterations of "n->n/2 if n even, n->3n-1 if n odd" (A001281) starting at these numbers reach 5.

5, 7, 9, 10, 13, 14, 18, 19, 20, 26, 27, 28, 35, 36, 38, 40, 47, 51, 52, 54, 56, 63, 70, 72, 75, 76, 80, 81, 89, 93, 94, 102, 104, 107, 108, 112, 119, 121, 125, 126, 133, 139, 140, 143, 144, 149, 150, 152, 159, 160, 161, 162, 167, 177, 178, 181, 186, 187, 188, 191

Offset

1,1

Links

Table of n, a(n) for n=1..60.

Mathematica

it5Q[n_]:=Last[NestWhileList[If[EvenQ[#], #/2, 3#-1]&, n, #!=5&, 1, 100]]==5; Select[Range[200], it5Q] (* Harvey P. Dale, May 09 2012 *)

Crossrefs

Cf. A037084, A039500-A039505.

Sequence in context: A005523 A037084 A018935 * A114255 A350496 A358314

Adjacent sequences: A039498 A039499 A039500 * A039502 A039503 A039504

Keyword

nonn,easy

Author

Christian G. Bower, Feb 15 1999

Status

approved