A006395 Number of unsensed planar maps with n edges and without loops or parallel edges.

1, 1, 1, 3, 5, 14, 42, 150, 624, 2947, 15079, 82607, 474030, 2816952, 17194524, 107226255

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• more

Comments

The planar maps considered here are connected. A planar map without loops or parallel edges is called simple.

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

Row sums of A384850, antidiagonal sums of A384963.

Cf. A006385, A006391, A006394 (sensed), A022558 (rooted), A372892 (with n vertices).

Extensions

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

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

a(13)-a(15) added by Andrew Howroyd, Jun 15 2025