# [seqfan] Re: Discrepancy between definition and terms in A257481?

Kival Ngaokrajang kival at psp.co.th
Wed May 20 02:53:14 CEST 2015

```Dear Neil & Seq fan,

I added illustrations into A257481 & A257594.

Best Regards,
Kival

-----Original Message-----
From: SeqFan [mailto:seqfan-bounces at list.seqfan.eu] On Behalf Of Neil Sloane
Sent: Tuesday, May 19, 2015 2:42 AM
To: Sequence Fanatics Discussion list
Subject: [seqfan] Re: Discrepancy between definition and terms in A257481?

I agree there is something very wrong with A257481.
The original definition was unclear to me, so I made a guess, which was obviously wrong.

I will replace the definition with a new guess, and assign the present defintion, which seems to give the values
0,0,0,0,0,0,1,1,2,3,4,5,7 (for n >= 0) to a new sequence  A257954

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.
Email: njasloane at gmail.com

On Mon, May 18, 2015 at 4:27 PM, Brad Klee <bradklee at gmail.com> wrote:

> Hi Felix,
>
> The sequence is cross-referenced with A182619.
>
> "Number of vertices that are connected to two edges in a spiral
> without holes constructed with n hexagons."
>
> It could be that the "chain" is a linear object. For n=12 the chain
> would spiral around to enclose 3 of its "links" with the other 9 circles.
>
> I agree it is confusing, and could maybe use an illustration.
>
> Thanks,
>
>
>
>
> On Mon, May 18, 2015 at 3:20 AM, Felix FrÃ¶hlich
> >
> wrote:
>
> > Dear SeqFans
> >
> > the definition says "a(n) is the maximal number of circles that can
> > be enclosed by a chain of n circles". So why does the example say
> > "For a(7), one circle can be completely enclosed by six surrounding
> > circles"? Isn't that an example for the value of a(6)? Same goes for
> > the example for
> a(10).
> > Shouldn't a(10), by the definition of the sequence, give the maximum
> number
> > of circles that can be surrounded by a chain of ten circles? Or am I
> simply
> > completely misunderstanding something about the sequence? Can
> > someone clarify how the definition, example and terms of the
> > sequence correlate
> to
> > each other?
> >
> > Best regards
> > Felix FrÃ¶hlich
> >
> > _______________________________________________
> >
> > Seqfan Mailing list - http://list.seqfan.eu/
> >
>
> _______________________________________________
>
> Seqfan Mailing list - http://list.seqfan.eu/
>

_______________________________________________

Seqfan Mailing list - http://list.seqfan.eu/
```