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URL: https://oeis.org/A006395

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A006395
Number of unsensed planar maps with n edges and without loops or parallel edges.
5
1, 1, 1, 3, 5, 14, 42, 150, 624, 2947, 15079, 82607, 474030, 2816952, 17194524, 107226255
OFFSET
0,4
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).
Sequence in context: A318227 A363542 A230585 * A078718 A081393 A338368
KEYWORD
nonn,more
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
STATUS
approved