[seqfan] Re: A000105 Free Polyominoes

[Tom Duff]

Doesn't look like it's in that paper, which I found here:
https://dspace.jaist.ac.jp/dspace/bitstream/10119/13757/1/21457.pdf
Possibly this: https://www.gathering4gardner.org/g4g10gift/math/Shirakawa_Toshihiro-Harmonic_Magic_Square.pdf
I think there's a more legit reference describing how Shirakawa counts
them, but it's not mentioned in his G4G paper and I can't find it
right now.
The obvious way to get free polyomino counts is to count fixed
polyominoes with various symmetries and use the Frobenius-Burnside
counting formula.

On Tue, Mar 9, 2021 at 9:25 AM John Mason <masonmilan33 at gmail.com> wrote:
>
> Hi seqfans,
> A000105 lists the numbers of free polyominoes through a(45).
> Wikipedia on the other hand states that values are known through a(28).
> I assume the new data comes from  “D. Xu, T. Horiyama, T. Shirakawa, R. Uehara, Common Developments of Three Incongruent Boxes of Area 30, in Proc. 12th Annual Conference, TAMC 2015, Singapore, May 18-20, 2015, LNCS Vol. 9076, pp. 236-247.”
> Would anyone with access to the article like to update Wikipedia?
> john
>
>
>
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