A006394 Number of sensed planar maps with n edges and without loops or parallel edges. (Formerly M2498)

1, 1, 1, 3, 5, 15, 52, 213, 1002, 5167, 27967, 158447, 926786

Offset

0,4

Comments

The planar maps considered here are connected. A planar map without loops or parallel edges is called simple. - Andrew Howroyd, Jan 16 2025

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. A006384, A006390, A006395 (unsensed), A022558 (rooted).

Sequence in context: A018601 A190733 A211344 * A018650 A177814 A018702

Adjacent sequences: A006391 A006392 A006393 * A006395 A006396 A006397

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

a(9)-a(12) from Sean A. Irvine, Mar 30 2017

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

Status

approved