[seqfan] Re: Another planetary sequence

[Felix Fröhlich]

Thanks for the replies.

Yes, the sequence is certainly time-dependent and the values are not
integers. For example, Triton is predicted to collide with Neptune in about
3.6 billion years, which will probably result in Triton's destruction.

The three sequences that come up when searching for A171467 are
interesting. Maybe I can come up with something similar.

Felix

2016-09-11 19:29 GMT+02:00 Alonso Del Arte <alonso.delarte at gmail.com>:

> For what it's worth, I would say no. Can you guarantee that nothing is
> going to happen to the moons of the outer planets that would render these
> numbers outdated?
>
> I have much greater confidence in a sequence like A171467, which lists
> transits of Venus. Even if something happens that causes the future
> transits of occur on different years than predicted, we still have a good
> number of documented transits since the 13th Century or earlier. Someone
> searching for "1874, 1882, 2004, 2012" will not be disappointed.
>
> Al
>
> On Sun, Sep 11, 2016 at 12:57 PM, Neil Sloane <njasloane at gmail.com> wrote:
>
> > my personal feeling is that that planetary sequence isn't quite
> interesting
> > enough
> > for an OEIS entry.  The terms are not integers, and they are certainly
> > time-dependent.
> > Of course the OEIS may not be around in a billion years, but still!
> >
> > Best regards
> > Neil
> >
> > Neil J. A. Sloane, President, OEIS Foundation.
> > 11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
> > Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
> > Phone: 732 828 6098; home page: http://NeilSloane.com
> > Email: njasloane at gmail.com
> >
> >
> > On Sun, Sep 11, 2016 at 12:49 PM, Felix Fröhlich <felix.froe at gmail.com>
> > wrote:
> >
> > > Dear sequence fans
> > >
> > > I thought about the following sequence:
> > >
> > > Ratio of radius of n-th planet (under the current IAU-definition of
> > planet)
> > > from the Sun to mean radius of its largest natural satellite, rounded
> to
> > > the nearest integer, or 0 if the planet has no natural satellite.
> > >
> > > a(1)-a(8) are 0, 0, 4, 308, 27, 23, 32, 18
> > >
> > > The true ratios are of course not integer values, but the terms give an
> > > idea of how large the largest moons of the planets are compared to the
> > > planets themselves (i.e. these values are still useful for comparison,
> > even
> > > when rounded to integers in my opinion). The closer the value is to 1,
> > the
> > > larger the largest moon is relative to its planet. The value for
> Earth's
> > > moon is relatively small, meaning the Moon is large relative to Earth.
> > >
> > > There are already a number of sequences related to the planets in the
> > OEIS,
> > > but I would like to hear the opinion of other contributors and/or some
> of
> > > the editors before submitting this, mainly because I think the sequence
> > > will likely be rejected.
> > >
> > > It is probably a "dumb" sequence, not really mathematically
> significant,
> > > but sometimes such sequences are still enjoyable.
> > >
> > > Best regards
> > > Felix
> > >
> > > --
> > > Seqfan Mailing list - http://list.seqfan.eu/
> > >
> >
> > --
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> >
>
>
>
> --
> Alonso del Arte
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> <https://www.smashwords.com/profile/view/AlonsoDelarte>
> Musician at ReverbNation.com <http://www.reverbnation.com/alonsodelarte>
>
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