[seqfan] Re: Polyominoes (A000105, A000988, A001168) - offset problem

Sean A. Irvine sairvin at gmail.com
Wed Jun 24 21:00:50 CEST 2020


I'm with Fred on this.  The current values are all correct and consistent,
but indeed a(0)=1 could be inserted as Fred suggests.


On Thu, 25 Jun 2020 at 03:51, Fred Lunnon <fred.lunnon at gmail.com> wrote:

>   A000105 with offset = 0  is correct as it currently stands:
> there is 1 empty polyomino with  #cells = 0 .
>
>   My preference would be to attach an extra 1 at the front of both
> A000988 and A001168 , and edit to  offset = 0.
>
>   All three should cross-refer to the others; and similar remarks
> may apply to related sequences, such as A030228.   NJAS ?
>
> Fred Lunnon
>
>
> On 6/24/20, Jean-Luc Manguin <jean-luc.manguin at unicaen.fr> wrote:
> > Hello,
> >
> > Everytime I edit a sequence, I receive justified remarks about my
> > non-respect of some rules, although of course this non-respect is not
> done
> > by purpose.
> >
> > In return, I would like to find in OEIS a care about coherence ; this
> > example needs (IMO) a little correction :
> > - A000105 has an offset = 0
> > - A000988 and A001168 have offset = 1
> >
> > These three sequences give the number of polyominoes (free, one-sided,
> and
> > fixed) and as it is written in the dedicated page in Mathworld, [
> > https://mathworld.wolfram.com/Polyomino.html |
> > https://mathworld.wolfram.com/Polyomino.html ] , there is no polyomino
> with
> > zero cell ; then I would be pleased to see A000105 with offset = 1, which
> > seems much more logical. Of course I could edit this sequence (I did not
> > try, I guess I can), but I prefer to mention this in the list.
> >
> > Thank you, dear editors, for your attention to this message.
> > Have a nice day and a happy St John !
> >
> > JL Manguin
> >
> >
> > --
> > Seqfan Mailing list - http://list.seqfan.eu/
> >
>
> --
> Seqfan Mailing list - http://list.seqfan.eu/
>


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