[seqfan] Re: Planar distributive lattices

[Allan Wechsler]

I think writing to him is a great idea; get him to author that sequence,
which he only deserves, after all.

On Sun, Apr 18, 2021 at 1:39 AM Neil Sloane <njasloane at gmail.com> wrote:

> PS I see that the author of that poster updated it in 2014, extending it to
> 15 vertices:
>
>
> https://math.chapman.edu/~jipsen/tikzsvg/planar-distributive-lattices15.html
>
> I am going to write to him
>
>
> Best regards
> Neil
>
> 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 Sun, Apr 18, 2021 at 1:17 AM Neil Sloane <njasloane at gmail.com> wrote:
>
> > Allan, I confirm your numbers.  I'll run it through Superseeker, which
> > will tell us if it is a simple cousin of an existing entry, and if it
> > doesn;t find anything I will add it - it will be A343161.
> >
> > Thanks for catching this fish!
> >
> > Best regards
> > Neil
> >
> > 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 Sat, Apr 17, 2021 at 9:22 PM Allan Wechsler <acwacw at gmail.com> wrote:
> >
> >> I forget how I stumbled on this:
> >>
> >>
> https://math.chapman.edu/~jipsen/mathposters/Planar%20distributive%20lattices%20up%20to%20size%2011.pdf
> >> .
> >>
> >> It is a chart purporting to show all of the planar distributive lattices
> >> with up to 11 vertices. Like any true-hearted sequence fanatic I counted
> >> the number of these guys of each order, and got the following sequence:
> >>
> >> 1,1,1,2,3,5,8,14,24,42,72...
> >>
> >> Imagine my surprise at finding this sequence missing from OEIS! The
> author
> >> is apparently Dr. Peter Jipsen, at Chapman University in California.
> >>
> >> Perhaps someone here can figure out (a) what a planar distributive
> lattice
> >> is, (b) whether Dr. Jipsen enumerated them correctly, (c) whether I
> >> counted
> >> them off Jipsen's poster correctly, and (d) whether to add the sequence.
> >>
> >> Thank you!
> >>
> >> --
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> >>
> >
>
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