A087255 Number of different initial values for 3x+1 trajectories of which the largest term appearing during the iteration equals n.

1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 12, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 3, 0, 0, 0, 1, 0

Offset

1,16

Links

Jon E. Schoenfield, Table of n, a(n) for n = 1..10000

Example

a(2k+1)=a(4k+2)=a(16k+12)=0 because larger values appear in iteration: 6k+4, 6k+4, and 18k+16, respectively. Exception: a(1)=a(2)=1.
Some outstanding cases: a(9232)=1579, a(13120)=75.

Crossrefs

Cf. A025586, A087251-A087254.

Sequence in context: A087936 A089804 A270606 * A097606 A201995 A226784

Adjacent sequences: A087252 A087253 A087254 * A087256 A087257 A087258

Keyword

nonn

Author

Labos Elemer, Sep 08 2003

Extensions

Edited by Jon E. Schoenfield, Dec 01 2013

Status

approved