A006400 Number of connected planar maps without vertices of degree 1. (Formerly M1404)

1, 1, 2, 5, 11, 33, 117, 431, 1755, 7485

Offset

3,3

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=3..12.

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

Crossrefs

Sequence in context: A056365 A276548 A353016 * A254342 A080068 A226919

Adjacent sequences: A006397 A006398 A006399 * A006401 A006402 A006403

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

a(11) and a(12) from Sean A. Irvine, Mar 30 2017

Status

approved