OFFSET
1,1
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Wormald, Nicholas C. Counting unrooted planar maps, Discrete Math. 36 (1981), no. 2, 205-225.
T. R. S. Walsh, Number of sensed planar maps with n edges and m vertices
CROSSREFS
KEYWORD
nonn,nice
AUTHOR
STATUS
approved