login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A097030 Numbers in the cycle-attractors of length=14 if the function f(x)=A063919(x) is iterated; f(x) is the sum of unitary proper divisors. 21
2418, 2958, 3522, 3534, 3582, 3774, 3906, 3954, 3966, 3978, 4146, 4158, 4434, 4446, 24180, 29580, 35220, 35238, 35340, 35820, 37740, 38682, 39060, 39540, 39660, 39780, 41460, 41580, 44340, 44460, 45402, 49878, 65190, 65322, 74430, 74610, 74790, 98106, 101478, 117258, 117270, 117450 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This sequence collects 14-cycle-attractor elements for iteration of sum-proper-unitary-divisors.

A002827 provides 1-cycle terms = unitary perfect numbers.

A063991 gives 2-cycle elements = unitary amicable numbers.

A097024 collects true 5-cycle elements, i.e., terms in end-cycle of length 5 when A063919(x) function is iterated.

Concerning 3-cycle elements, only {30,42,54} were encountered.

LINKS

Table of n, a(n) for n=1..42.

J. O. M. Pedersen, Known Unitary Sociable Numbers of order different from four [Via Internet Archive Wayback-Machine]

J. O. M. Pedersen, Order 14 cycles, 2007.

EXAMPLE

These 42 numbers are in 3 different 14-cycles. The first is: [2418, 2958, 3522, 3534, 4146, 4158, 3906, 3774, 4434, 4446, 3954, 3966, 3978, 3582]. [edited by Michel Marcus, Sep 29 2018]

CROSSREFS

Cf. A063919, A002827, A063991, A097024.

Sequence in context: A159346 A256835 A237940 * A204367 A131759 A254901

Adjacent sequences:  A097027 A097028 A097029 * A097031 A097032 A097033

KEYWORD

nonn

AUTHOR

Labos Elemer, Aug 30 2004

EXTENSIONS

More terms from Michel Marcus, Sep 29 2018

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 12 20:12 EST 2019. Contains 329961 sequences. (Running on oeis4.)