[seqfan] Re: apparently unique infinite sequences related to the sum of divisors
njasloane at gmail.com
Thu Jul 9 21:49:18 CEST 2015
Max, You said:
I have verified that all its values below 10^10 are uniquely
defined (all possible bifurcations die sooner or later). So we can be sure
that there is no dead end for A259934.
Me: But it is possible that A259934 reaches a dead end after 10^100
steps, right? So then we would need to backtrack and change A259934.
I don't see that any finite amount of checking will show we are on the
But I don't read Russian ....
I agree this is a very nice sequence!
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 Thu, Jul 9, 2015 at 3:22 PM, Max Alekseyev <maxale at gmail.com> wrote:
> Falcao proved that there is an infinite sequence starting with 2 (or 0 if
> you like). I have verified that all its values below 10^10 are uniquely
> defined (all possible bifurcations die sooner or later). So we can be sure
> that there is no deadend for A259934. It is an open question though if
> there exists a viable bifurcation point.
> On Thu, Jul 9, 2015 at 3:06 PM, <israel at math.ubc.ca> wrote:
> > How do you know your values for A259934 are correct? It's true that a(n)
> > d(a(n)) = a(n-1) for the listed values, but how do you know you don't run
> > into a dead end? Falcao apparently (I don't read Russian) proved there is
> > an infinite sequence, but there are also long finite sequences that have
> > dead ends.
> > Cheers,
> > Robert
> > On Jul 9 2015, Max Alekseyev wrote:
> > SeqFans,
> >> I'd like to draw your attention to two newly added nice sequences:
> >> http://oeis.org/A259934
> >> http://oeis.org/A259935
> >> Comments are welcome.
> >> Regards,
> >> Max
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