A006389 Number of unsensed planar maps with n edges and without faces of degree 1. (Formerly M1632)

1, 2, 6, 18, 68, 313, 1592, 9187, 57451, 384450, 2703970, 19769311

Offset

1,2

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=1..12.

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

Crossrefs

Cf. A006385.

Sequence in context: A150080 A150081 A006674 * A030269 A150082 A177470

Adjacent sequences: A006386 A006387 A006388 * A006390 A006391 A006392

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

a(8)-a(12) from Sean A. Irvine, Mar 28 2017

Status

approved