A006392 Number of sensed planar maps with n edges and without faces of degree 1 or 2.

1, 0, 1, 4, 9, 34, 161, 830, 4779, 29092, 184510, 1208178, 8116922

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. A006384, A006388, A006393 (unsensed), 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