A375280 Largest value in the trajectory of n in the A375265 map.

1, 2, 3, 4, 16, 6, 52, 8, 9, 16, 52, 12, 40, 52, 16, 16, 52, 18, 88, 20, 52, 52, 160, 24, 88, 40, 27, 52, 88, 30, 9232, 32, 52, 52, 160, 36, 112, 88, 40, 40, 9232, 52, 196, 52, 45, 160, 9232, 48, 148, 88, 52, 52, 160, 54, 9232, 56, 88, 88, 304, 60, 184, 9232, 63

Offset

1,2

Comments

By definition the trajectory ends when 1 is reached, so a(1) = 1.

Links

Paolo Xausa, Table of n, a(n) for n = 1..10000

Index entries for sequences related to 3x+1 (or Collatz) problem.

Formula

a(n) = max{A375266(n,k) for 1 <= k <= A375267(n) + 1}.

Example

a(10) = 16 because 16 is the largest value in the trajectory 10 -> 5 -> 16 -> 8 -> 4 -> 2 -> 1.

Mathematica

A375265[n_] := Which[Divisible[n, 3], n/3, Divisible[n, 2], n/2, True, 3*n + 1];
Array[Max[NestWhileList[A375265, #, # > 1 &]] &, 100]

Crossrefs

Cf. A375265, A375266, A375267.

Cf. A025586, A365478.

Sequence in context: A217714 A076965 A370694 * A113232 A095261 A066103

Adjacent sequences: A375277 A375278 A375279 * A375281 A375282 A375283

Keyword

nonn,easy

Author

Paolo Xausa, Aug 09 2024

Status

approved