OFFSET
6,4
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
N. J. A. Sloane, Table of n, a(n) for n = 6..50
T. R. S. Walsh, Number of sensed planar maps with n edges and m vertices
T. R. S. Walsh, Counting nonisomorphic three-connected planar maps, J. Combin. Theory Ser. B 32 (1982), no. 1, 33-44.
FORMULA
a(n) = Sum_{k=4..n-2} A239893(k, n+2-k). - Andrew Howroyd, Mar 27 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms and b-file added by N. J. A. Sloane, May 08 2012
STATUS
approved