A006445 Number of n-edge 3-connected planar maps with a sense-reversing automorphism.

0, 0, 0, 0, 0, 1, 0, 1, 2, 1, 4, 9, 12, 27, 50, 99, 188, 386, 740, 1528, 3012, 6192, 12376, 25594, 51628, 107135, 218100, 453895, 930812, 1943281, 4009512, 8394915, 17414512

Offset: 1

Author

N. J. A. Sloane, T. R. S. Walsh, personal communication

Keywords

• nonn

Comments

Maps are counted up to isomorphism which is not restricted to those that preserve the orientation of the sphere.

References

• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
• Computed by Nick Wormald (unpublished).

Links

• T. R. S. Walsh, Number of sensed planar maps with n edges and m vertices