Counting Self-intersecting n-gons

[David Wilson]

No three edges share a common point.  Three edges are allowed
to intersect pairwise.


----- Original Message ----- 
From: "Brendan McKay" <bdm at cs.anu.edu.au>
To: <ham>; "Sequence Fans" <seqfan at ext.jussieu.fr>
Sent: Friday, April 22, 2005 7:24 AM
Subject: Re: Counting Self-intersecting n-gons


>* David Wilson <davidwwilson at comcast.net> [050422 21:21]:
>> Define a self-intersecting polygon as a polygon in which any two
>> edges may intersect at a single nonvertex point, but no three edges
>> may intersect.
> 
> Please clarify whether you mean three edges intersecting in a single
> point or intersecting pairwise.
> 
> Thanks, Brendan.