[seqfan] Re: Giving a mathematical definition to A280001

[Natan Consigli]

Also, I have to mention that the graphs are three-dimensional for
stereoisomer distinction

On Wed, Feb 1, 2017 at 5:57 AM, Natan Consigli <origami.experience at gmail.com
> wrote:

> Dear Seqfans,
>
> I am trying to define A280001 mathematically with graph theory. To let the sequence be less "obscure" I have to define what does chemical aromaticity mean.
>
> Here is what I did so far.
>
> As far as being a hydrocarbon I am looking for a connected multigraph (non looped for some authors) where each node has degree less than five (octet rule).
>
> For the condition of being aromatic I need a connected subset of nodes that satisfies Huckel's rule. This means that such subset must have the following:
>
> 1) an alternating connection 1-edge/2-edge vertices (conjugated pi system);
>
> 2) the number of 2-edge connections must be odd (4n+2 pi electrons);
>
> 3) the subset of nodes must represent a chemically planar portion of the molecule.
>
> I find stating rule 3 in a mathematical way very hard to do. If anybody has ideas I would appreciate your help.
>
> Natan Consigli
>
>