A222562 Numbers that are highest in their respective Collatz (3x+1) trajectories only.

1, 2, 4, 8, 20, 24, 32, 48, 56, 68, 72, 80, 84, 96, 104, 116, 128, 132, 144, 152, 168, 176, 180, 192, 200, 212, 224, 228, 240, 260, 264, 272, 276, 288, 296, 308, 312, 320, 324, 336, 344, 356, 360, 368, 372, 384, 392, 404, 408, 416, 452, 456, 464, 468, 480, 488

Offset

1,2

Comments

This is effectively the complement of A176869 in A033496, excluding numbers which are also highest in trajectories less than the number itself.

Links

T. D. Noe, Table of n, a(n) for n = 1..1000

Mathematica

Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; oldMax = {}; t = {}; Do[c = Collatz[n]; If[! MemberQ[oldMax, n] && Max[c] == n, AppendTo[t, n]]; oldMax = Union[oldMax, {Max[c]}], {n, 416}]; t (* T. D. Noe, Feb 28 2013 *)

Crossrefs

Cf. A033496, A176869.

Sequence in context: A217520 A124154 A296606 * A252891 A102634 A026520

Adjacent sequences: A222559 A222560 A222561 * A222563 A222564 A222565

Keyword

nonn

Author

Jayanta Basu, Feb 27 2013

Status

approved