[seqfan] Re: Keyword:cons sequences in Maple

Neil Sloane njasloane at gmail.com
Wed Apr 9 14:43:55 CEST 2014


Ah, but isn't it true that the sequence of digits is just a means
of identifying the number one is interested in, and once
one has found it, one wants a program that will compute
the real number, and not the digit stream?
Neil


On Wed, Apr 9, 2014 at 8:22 AM, Alonso Del Arte <alonso.delarte at gmail.com>wrote:

> Reason I ask is because there seem to be some 300 entries in the OEIS using
> digits and evalf but only recently has an objection been raised to that it
> gives something like
>
> 1.414213562373...
>
> rather than
>
> 1, 4, 1, 4, 2, 1, 3, 5, 6, 2, 3, 7, 3, ...
>
> Al
>
>
> On Wed, Apr 9, 2014 at 7:30 AM, M. F. Hasler <seqfan at hasler.fr> wrote:
>
> > The shortest direct implementation might be
> > seq( `if`(c=".",NULL,parse(c)), c=convert( evalf[N](x) ,string))
> >
> > Maximilian
> >
> >
> > On Tue, Apr 8, 2014 at 10:26 PM, <israel at math.ubc.ca> wrote:
> > >
> > > Actually, you can use RealDigits in the MmaTranslator[Mma] package:
> > >
> > >> MmaTranslator[Mma][RealDigits](evalf[100](sqrt(2)));
> > >
> > >
> > > [[1, 4, 1, 4, 2, 1, 3, 5, 6, 2, 3, 7, 3, 0, 9, 5, 0, 4, 8, 8, 0, 1, 6,
> > 8, 8, 7, 2, 4, 2, 0, 9, 6, 9, 8, 0, 7, 8, 5, 6, 9, 6, 7, 1, 8, 7, 5, 3,
> 7,
> > 6, 9, 4, 8, 0, 7, 3, 1, 7, 6, 6, 7, 9, 7, 3, 7, 9, 9, 0, 7, 3, 2, 4, 7,
> 8,
> > 4, 6, 2, 1, 0, 7, 0, 3, 8, 8, 5, 0, 3, 8, 7, 5, 3, 4, 3, 2, 7, 6, 4, 1,
> 5,
> > 7, 3, 0, 0, 0, 0], 1]
> > >
> > > (Hmm: I don't know why it puts in those extra four 0's).
> > >
> > > Or you can do this:
> > >>
> > >> ListTools:-Reverse(convert(round(10^99*sqrt(2)),base,10));
> > >
> > >
> > > [1, 4, 1, 4, 2, 1, 3, 5, 6, 2, 3, 7, 3, 0, 9, 5, 0, 4, 8, 8, 0, 1, 6,
> 8,
> > 8, 7, 2, 4, 2, 0, 9, 6, 9, 8, 0, 7, 8, 5, 6, 9, 6, 7, 1, 8, 7, 5, 3, 7,
> 6,
> > 9, 4, 8, 0, 7, 3, 1, 7, 6, 6, 7, 9, 7, 3, 7, 9, 9, 0, 7, 3, 2, 4, 7, 8,
> 4,
> > 6, 2, 1, 0, 7, 0, 3, 8, 8, 5, 0, 3, 8, 7, 5, 3, 4, 3, 2, 7, 6, 4, 1, 5,
> 7,
> > 3]
> > >
> > > Robert Israel
> > > University of British Columbia and D-Wave Systems
> > >
> > >
> > >
> > > On Apr 8 2014, Alonso Del Arte wrote:
> > >
> > >> Is there a recommended way in Maple to compute keyword:cons sequences?
> > Like
> > >> for example 1/sqrt(2) ?
> > >>
> > >> (In Mathematica, that would be something like RealDigits[1/Sqrt[2]
> etc.)
> > >>
> > >> Al
> > >>
> > >>
> > >
> > > _______________________________________________
> > >
> > > 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/
>



-- 
Dear Friends, I have now retired from AT&T. New coordinates:

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


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