A006396 Number of planar maps with n edges and without faces or vertices of degree 1. (Formerly M1238)

1, 2, 4, 10, 36, 132, 616, 3060, 16207, 88990, 503816

Offset

2,2

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=2..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: A354963 A188495 A038077 * A192502 A243567 A323949

Adjacent sequences: A006393 A006394 A006395 * A006397 A006398 A006399

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

a(9)-a(12) from Sean A. Irvine, Mar 28 2017

Status

approved