[seqfan] Re: Bad pdf file in A002369?

jnthn stdhr jstdhr at gmail.com
Sun Feb 25 20:41:49 CET 2018


 Is anyone aware of any papers related to grouping polyominoes according to
partitions of n?  After correcting an omission for n=5, I found the
sequence mentioned earlier is A056780.  Correcting the irregular triangle I
mentioned in a seperate post I now get:

1                            = 1
1 1                          = 2
1 1 1                        = 3
1 2 2 3 1                    = 9
1 2 2 7 5 3 1                = 21


But this triangle is still not in the database.  Read by rows, this
lists the number of polyrects that can be built by grouping the
rectangles into blocks based on the partition sets for n found in
A080577.


These images illustrate what I am talking about:  https://imgur.com/a/qHO2l

The first image shows n={1,2,3,4}, and the next two images show n=5.


Jonathan




On Sun, Feb 25, 2018 at 11:37 AM, jnthn stdhr <jstdhr at gmail.com> wrote:

> Is anyone aware of any papers related to grouping polyominoes according to
> partitions of n?  After correcting an omission for n=5, I found the
> sequence mentioned earlier is A056780.  Correcting the irregular triangle
> I mentioned in a seperate post I now get:
>
> 1                            = 1
> 1 1                          = 2
> 1 1 1                        = 3
> 1 2 2 3 1                    = 9
> 1 2 2 7 5 3 1                = 21
>
>
> But this triangle is not in the database.  Read by rows, this lists the number of polyrects that can be built by grouping the rectangles into blocks based on the partition sets for n found in A080577.
>
>
> These images illustrate what I am talking about:  https://imgur.com/a/qHO2l
>
> The first image shows n={1,2,3,4}, and the next two images show n=5.
>
>
> Jonathan
>
>
>
> On Sun, Feb 25, 2018 at 9:39 AM, Joerg Arndt <arndt at jjj.de> wrote:
>
>> * Fred Lunnon <fred.lunnon at gmail.com> [Feb 25. 2018 18:28]:
>> >   Partly ... but if you do need an "intelligent" program to progress
>> further
>> > (after comparing early terms with the "simple" one), then reverse
>> > "modding out" to recover the fixed counts as well; and publish both
>> > free and fixed counts.
>>
>> Well, I at first had no modding out in the code
>> and made sure the sequences are in the OEIS,
>> in fact having more terms than I could get.
>>
>> >
>> >   Another feature of fixed counts is that they are typically smoother
>> than
>> > free, so that empirical estimates of asymptotic behaviour are more
>> > consistent using the same amount of data.
>> >
>> > WFL
>>
>> Thanks and best regards,   jj
>>
>>
>> > [...]
>>
>> --
>> Seqfan Mailing list - http://list.seqfan.eu/
>>
>
>


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