

A078672


Number of simple 4regular 4edgeconnected but not 3connected plane graphs on n nodes.


2



0, 0, 0, 0, 0, 0, 1, 1, 6, 16, 59, 188, 685, 2412, 8825, 32110, 118505
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OFFSET

6,9


LINKS

Table of n, a(n) for n=6..22.
A. Caudron, Classification des noeuds et des enlacements Public. Math. d'Orsay 82. Orsay: Univ. Paris Sud, Dept. Math., 1982.
S. V. Jablan, Ordering Knots
S. V. Jablan, L. M. Radović, and R. Sazdanović, Basic polyhedra in knot theory Kragujevac J. Math., 28 (2005), 155164.


EXAMPLE

The first such graph has 12 nodes. It is called 12E [Jablan, Radović & Sazdanović, Fig. 2; or Caudron, p. 308c] and looks like that:
___________
/ \
/ OO OO
/\ /\ /\ /
O  O  O  O 
\/ \/ \/ \
\ OO OO
\___________/


CROSSREFS

A078666 = A007022 + this sequence.
Sequence in context: A223028 A091649 A125628 * A219817 A120795 A118640
Adjacent sequences: A078669 A078670 A078671 * A078673 A078674 A078675


KEYWORD

nonn


AUTHOR

Slavik V. Jablan (jablans(AT)yahoo.com) and Brendan McKay Feb 06 2003


STATUS

approved



