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

[Jean-François Alcover]

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/
> >
> >
> >     --
> >     Seqfan Mailing list - http://list.seqfan.eu/
> >
>
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