A006444 Number of achiral 2-connected planar maps with n edges.

0, 1, 2, 3, 6, 14, 30, 77, 196, 525, 1414, 3960, 11056, 31636, 90818, 264657, 774146, 2289787, 6798562, 20354005, 61164374, 184985060, 561433922, 1712696708, 5241637812

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

References

• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
• T. R. S. Walsh, personal communication.

Links

• Timothy R. Walsh, Number of sensed planar maps with n edges and m vertices, p. 44.

Crossrefs

Cf. A006402 (sensed), A006403 (unsensed), A006443 (connected), A006445 (3-connected).