login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A226661 Smallest positive integer k (or 0 if no such k) with a primitive cycle of positive integers, exactly n of which are odd, under iteration by the Collatz-like 3x+k function. 3
1, 7, 5, 25, 13, 59, 47, 11, 29, 145, 59, 31, 115, 79, 13, 47, 5, 17, 125, 79, 263, 49, 169, 91, 191, 23, 601, 323, 193, 109, 311, 73, 149, 265, 571, 95, 491, 697, 695, 137, 29, 119, 383, 575, 283, 121, 263, 233, 163, 193, 283, 479, 107, 203, 437, 85, 491, 349 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A cycle is called primitive if its elements are not a common multiple of the elements of another cycle.

The 3x+k function T_k is defined by T_k(x) = x/2 if x is even, (3x+k)/2 if x is odd, where k is odd.

For primitive cycles, GCD(k,6)=1.

Conjecture: a(n)>0 for all n.

LINKS

Geoffrey H. Morley, Table of n, a(n) for n = 1..2520

CROSSREFS

Cf. A226610, A226660, A226677.

Sequence in context: A213835 A145396 A263825 * A120404 A334784 A146619

Adjacent sequences: A226658 A226659 A226660 * A226662 A226663 A226664

KEYWORD

nonn

AUTHOR

Geoffrey H. Morley, Jul 05 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 27 21:40 EST 2022. Contains 358406 sequences. (Running on oeis4.)