[seqfan] Description of A007297 incorrect

Axel Boldt axelboldt at yahoo.com
Thu Nov 5 02:11:52 CET 2015


The description of A007297 says 

"Number of connected graphs on n nodes on a 
circle without crossing edges." 

It's not clear what difference it makes that
the nodes lie on a circle.

I think we want instead 

"Number of connected graphs on n labeled nodes 
on a circle with straight-line edges that don't 
cross."

But even then we'd get the sequence (starting 
with n=1): 1,1,4,23,156,..., so the initial 1 
is missing.

I'm not sure how to fix it; maybe have two 
separate entries, one for the g.f. series 
reversion of A162395 and the other for the above 
graph counting sequence?
 Axel



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