[seqfan] Re: graphs with odd degrees

Neil Sloane njasloane at gmail.com
Sun Apr 8 15:34:44 CEST 2012


Brendan, Good point!

We do allow bisections of sequences, especially when they have
an independent existence, so the entries should be updated as you suggest.

Neil

On Sun, Apr 8, 2012 at 9:29 AM, Brendan McKay <bdm at cs.anu.edu.au> wrote:

> > Message: 7
> > Date: Fri, 6 Apr 2012 16:34:09 +0300
> > From: Georgi Guninski <guninski at guninski.com>
> > To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
> > Subject: [seqfan] Re: graphs with odd degrees
> > Message-ID: <20120406133409.GH5365 at sivokote.iziade.m$>
> > Content-Type: text/plain; charset=us-ascii
> >
> > On Thu, Apr 05, 2012 at 11:27:41AM -0400, Neil Sloane wrote:
> > > Georgi, Tanya,
> > >
> > > This is the number of graphs on n unlabeled nodes all having odd
> degree,
> > > right?
> > >
> > > Please enter it in the OEIS! I'm surprised it's not
> > > there already.
> > >
> > > Neil
> > >
> >
> > Just submitted A182012 Number of graphs on n vertices all having odd
> > degrees .
> >
> > I am not familiar with graph theory so probably someone should
> > edit/extend it.
> >
> > --
> > Georgi
>
> The graphs on 2n vertices all having odd degrees are just the
> complements of those having all even degrees. That's why the
> property of all odd degrees is seldom mentioned.
>
> Therefore, this sequence is just every second term of A002854. I
> don't know if we allow this, but if we do then A182012 should
> mention it and A002854 should be used to extend A182012.
>
> Brendan.
>



-- 
Dear Friends, I will soon be retiring from AT&T. New coordinates:

Neil J. A. Sloane, President, OEIS Foundation
11 South Adelaide Avenue, Highland Park, NJ 08904, USA
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com



More information about the SeqFan mailing list