[seqfan] Re: Planar distributive lattices

[Neil Sloane]

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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>>
>