[seqfan] Re: Update on Java implementations of OEIS sequences

[Sean A. Irvine]

Hi Alonso,

I seemed to have missed your message earlier.

Yes, we have support for computing over rationals (if that is what you
mean).  This is mostly done with various classes in:

https://github.com/archmageirvine/joeis/tree/master/src/irvine/math/q

Sean.




On Wed, 23 Dec 2020 at 19:37, Alonso Del Arte <alonso.delarte at gmail.com>
wrote:

> It's a big project. I was looking around it for something to deal with
> fractions. It's not terribly difficult to make a Fraction class, if you
> don't already have one.
>
> Al
>
> P.S. I haven't forgotten about What's Special About This Fraction? I think
> I'll hold off on updates to next year.
>
> On Mon, Dec 21, 2020 at 5:04 PM Sean A. Irvine <sairvin at gmail.com> wrote:
>
> > Yes Neil, you understand exactly what I mean.  Something that would
> > actually help people understand how the table of known values is
> > determined.  It is fine for it to include rules like if n is prime then
> the
> > answer is 1 etc.  It seems like this is the kind of thing that would be
> > useful for all core sequences.  I'm sure the details are already all
> buried
> > in the various links and papers, but to non-experts it can be hard to
> trace
> > all that.
> >
> > Sean.
> >
> >
> > On Tue, 22 Dec 2020 at 10:58, Neil Sloane <njasloane at gmail.com> wrote:
> >
> > > PS  Sean,  if you allow any language, then MAGMA is surely the best bet
> > for
> > > those group theory sequences, and also for posets.
> > > Don't we have any Magma experts on the list?
> > >
> > > (I don't mean a cheating program, like a table lookup, although Magma
> > > does have extensive tables of small objects.  I'm talking about what
> you
> > > want, a program for extending the known values.)
> > >
> > > 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 Mon, Dec 21, 2020 at 4:49 PM Neil Sloane <njasloane at gmail.com>
> wrote:
> > >
> > > > Sean, Georg - 100000 programs, that's amazing!
> > > >
> > > > How does one find the program for a sequence?  I was curious to see
> > what
> > > > you do for the core sequence A000001, the number of groups of order
> > n.  I
> > > > went to https://github.com/archmageirvine/joeis, but I did not see
> how
> > > to
> > > > search for A000001.  Obviously I'm not a regular github user.
> > > >
> > > > And I didn't see any mention of Java in https://oeis.org/A000001
> > > >
> > > > 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 Mon, Dec 21, 2020 at 3:56 PM Sean A. Irvine <sairvin at gmail.com>
> > > wrote:
> > > >
> > > >> We are pleased to report that the jOEIS now covers over 100000 (29%)
> > of
> > > >> sequences from the database including over 95% of sequences below
> > > A037000
> > > >> and all but 5 of the "core" sequences.  We did not keep track, but
> > there
> > > >> have been many corrections and extensions in the OEIS as a result of
> > > this
> > > >> effort.
> > > >>
> > > >> We would both like to thank all the members of the seqfan community
> > that
> > > >> answered our various questions, provided example code, or helped
> with
> > > the
> > > >> review of the corresponding OEIS entry changes this year.  In
> > > particular,
> > > >> Joerg Arndt, Brian Galebach, Volker Gebhardt, Alois Heinz, Mong Lung
> > > Lang,
> > > >> Peter Luschny, Simon Plouffe, Seiichi Manyama, Michel Marcus,
> Richard
> > > >> Mathar, Neil Sloane, and Michael Somos.
> > > >>
> > > >> These are the remaining "core" sequences for which we do not have an
> > > >> implementation:
> > > >>
> > > >> A000019 Number of primitive permutation groups of degree n.
> > > >> A000112 Number of partially ordered sets ("posets") with n unlabeled
> > > >> elements.
> > > >> A000609 Number of threshold functions of n or fewer variables.
> > > >> A001034 Orders of non-cyclic simple groups (without repetition).
> > > >> A002106 Number of transitive permutation groups of degree n.
> > > >>
> > > >> It would be nice to have programs (real programs -- not a cheat like
> > the
> > > >> table lookup in A000019) for each of these in any language!
> > > >>
> > > >> Perhaps some of these would make good honors projects or part of a
> > > masters
> > > >> project.
> > > >>
> > > >> For more information about the jOEIS project, see
> > > >> https://github.com/archmageirvine/joeis
> > > >>
> > > >> Regards,
> > > >> Sean A. Irvine and Georg Fischer
> > > >>
> > > >> --
> > > >> Seqfan Mailing list - http://list.seqfan.eu/
> > > >>
> > > >
> > >
> > > --
> > > Seqfan Mailing list - http://list.seqfan.eu/
> > >
> >
> > --
> > Seqfan Mailing list - http://list.seqfan.eu/
> >
>
>
> --
> Alonso del Arte
> Author at SmashWords.com
> <https://www.smashwords.com/profile/view/AlonsoDelarte>
> Musician at ReverbNation.com <http://www.reverbnation.com/alonsodelarte>
>
> --
> Seqfan Mailing list - http://list.seqfan.eu/
>