[Graphs with n edges]

[Christian G. Bower]

"Dr. Arne Ring" <arne.ring at epost.de> wrote:
> Hello,
> 
> I'm new to this list and hope for some interesting discussions.
> Previously I have contributed some sequences about  the number of prime 
> factors on special numbers (such as n!+1).
> 
> Currently I'm working on special graphs, and I would like to mention the 
> following observation:
> 
> There are two lists in the data base, starting with 
> "1,1,1,3,5,12,30,79,227", the A046091 and A002905.
> Both state that they list the number of graphs with n edges.
> 

No!

A002905 states it's the number of [connected] graphs with n edges
A046091 states it's the number of [connected] PLANAR graphs with n edges
i.e. those graphs that can be drawn in the plane without edges crossing.

They are two different sequences.

By the way, the offset on A002905 should be 0, not 1.