A006393 Number of unsensed planar maps with n edges and without faces of degree 1 or 2.

1, 0, 1, 4, 9, 32, 132, 597, 3064, 17114, 102274, 643907, 4219540

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• more

References

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

Links

• Timothy R. Walsh, Generating nonisomorphic maps without storing them, SIAM J. Algebraic Discrete Methods 4 (1983), no. 2, 161-178.

Crossrefs

Cf. A006385, A006389, A006392 (sensed), A379434 (rooted).

Extensions

a(8)-a(12) from Sean A. Irvine, Mar 29 2017

a(0)-a(1) prepended by Andrew Howroyd, Jan 16 2025