[seqfan] Re: Keyword:cons sequences in Maple

Charles Greathouse charles.greathouse at case.edu
Wed Apr 9 14:43:20 CEST 2014


Honestly it doesn't bother me if programs for cons sequences give the
constant rather than the decimal digits. Except for easy sequences most of
the difficulty is in efficiently computing the constant itself rather than
base conversion which is routine.

Charles Greathouse
Analyst/Programmer
Case Western Reserve University


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
> > >>
> > >>
> > >
> > > _______________________________________________
> > >
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> > >
> >
> > _______________________________________________
> >
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> >
>
>
>
> --
> Alonso del Arte
> Author at SmashWords.com<
> https://www.smashwords.com/profile/view/AlonsoDelarte>
> Musician at ReverbNation.com <http://www.reverbnation.com/alonsodelarte>
>
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>
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>


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