A006399 Number of unsensed planar maps with n edges and without loops or isthmuses. (Formerly M1162)

1, 0, 1, 2, 4, 8, 27, 76, 295, 1188, 5462, 26580, 138110

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, A006391, A006398 (sensed), A099553 (rooted).

Sequence in context: A112285 A037170 A212409 * A326293 A324328 A056800

Adjacent sequences: A006396 A006397 A006398 * A006400 A006401 A006402

Keyword

nonn,more,changed

Author

N. J. A. Sloane

Extensions

a(9)-a(12) from Sean A. Irvine, Mar 29 2017

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

Status

approved