[seqfan] Re: graphs with odd degrees

Charles Greathouse charles.greathouse at case.edu
Thu Apr 5 18:50:31 CEST 2012


Glad to see that the sequences are now in the OEIS.

Tanya, perhaps you should add to the sequences the context in which
these sequences appeared?  It might be useful for the next person!

Charles Greathouse
Analyst/Programmer
Case Western Reserve University

On Thu, Apr 5, 2012 at 11:27 AM, Neil Sloane <njasloane at gmail.com> 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
>
> On Thu, Apr 5, 2012 at 6:34 AM, Georgi Guninski <guninski at guninski.com>wrote:
>
>> On Wed, Apr 04, 2012 at 09:03:09AM -0700, Tanya Khovanova wrote:
>> > Hello all,
>> >
>> > Me and my student are working on a project where we encountered graphs
>> with all odd degrees. I couldn't find the sequence in the OEIS. Will
>> someone like to generate it?
>> >
>> >
>> > We submitted two sequences:
>> > A210345 The number of degree sequences of simple graphs with n vertices
>> with all even degrees.
>> > and
>> > A210346 The number of degree sequences of simple graphs with 2n vertices
>> with all odd degrees.
>> >
>> > The sequences need more terms. And I do not know how to enumerate graphs
>> themselves.
>> >
>> > Tanya
>> >
>> > _______________________________________________
>> >
>> > Seqfan Mailing list - http://list.seqfan.eu/
>>
>> For enumerating non-isomorphic I use naytu [1] geng.
>> You can parse the graphs in whatever language, but since nauty is
>> optional package for sage I use it from sage.
>>
>> Attached is a sample sage implementation which agrees with your terms to
>> a(9).
>>
>>
>> [1] http://cs.anu.edu.au/~bdm/nauty/
>>
>>
>>
>> _______________________________________________
>>
>> Seqfan Mailing list - http://list.seqfan.eu/
>>
>>
>
>
> --
> 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
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>
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