[seqfan] Re: A063747 sign of power series expansion of the Gamma function

Sean A. Irvine sairvin at gmail.com
Fri May 19 21:34:28 CEST 2023


Yes, I will make an update.

Thank you Jean-François and Brendan for taking the time to verify.

Sean.



On Sat, 20 May 2023 at 07:04, Neil Sloane <njasloane at gmail.com> wrote:

> Well, if a(46) is wrong (which seems to be the case), could someone please
> make the correction?  And probably all the terms after a(46) should be
> deleted, and we should give it keyword "more".
>
>
> Best regards
> Neil
>
> Neil J. A. Sloane, Chairman, OEIS Foundation.
> Also Visiting Scientist, Math. Dept., Rutgers University,
> Email: njasloane at gmail.com
>
>
>
> On Fri, May 19, 2023 at 3:14 AM Jean-François Alcover <
> jf.alcover at gmail.com>
> wrote:
>
> > Mma's SeriesCoefficient[1/Gamma[1 - x], {x, 0, n}] // Sign gives -1 for
> > n=46 (after 15 mn !)
> >
> > Le ven. 19 mai 2023 à 06:52, Brendan McKay via SeqFan <
> > seqfan at list.seqfan.eu>
> > a écrit :
> >
> > > My typo, it is e-38.  Oops.  B/
> > >
> > > On 19/5/2023 1:11 pm, Allan Wechsler wrote:
> > > > One of you said "e-38" and the other said "e-58". Do you really have
> > > > 20 orders of magnitude of disagreement?
> > > >
> > > > On Thu, May 18, 2023 at 11:07 PM Brendan McKay via SeqFan
> > > > <seqfan at list.seqfan.eu> wrote:
> > > >
> > > >     I also get -0.444..e-58  * x^46 in Maple using 60 digits.  The
> > > >     calculation
> > > >     is numerically unstable though.
> > > >
> > > >     B/
> > > >
> > > >     On 19/5/2023 12:31 pm, Sean A. Irvine wrote:
> > > >     > Hi,
> > > >     >
> > > >     > I believe the terms in A063747 are incorrect for n>=46.
> > > >     >
> > > >     > https://oeis.org/A063747
> > > >     >
> > > >     > My attempts to reproduce the calculation in Maple and using
> > > >     constructible
> > > >     > reals in Java both yield a coefficient, like -0.44458...e-38 *
> > > >     x^46, from
> > > >     > which a(46) should be -1 rather than 1.
> > > >     >
> > > >     > Is someone able to make an independent check?
> > > >     >
> > > >     > I was unable to run the existing Pari program beyond n=15, but
> I
> > > >     assume
> > > >     > there is some way to tell Pari to try harder?
> > > >     >
> > > >     > (I previously emailed the author of the sequence, but received
> > > >     no response.)
> > > >     >
> > > >     > Sean.
> > > >     >
> > > >     > --
> > > >     > Seqfan Mailing list - http://list.seqfan.eu/
> > > >
> > > >
> > > >     --
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