A006393 Number of unsensed planar maps with n edges and without faces of degree 1 or 2. (Formerly M3367)

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

Offset

0,4

References

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

Links

Table of n, a(n) for n=0..12.

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).

Sequence in context: A382790 A129196 A119574 * A320920 A368683 A048757

Adjacent sequences: A006390 A006391 A006392 * A006394 A006395 A006396

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

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

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

Status

approved