%I M1404 #16 Mar 30 2017 15:26:17
%S 1,1,2,5,11,33,117,431,1755,7485
%N Number of connected planar maps without vertices of degree 1.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H Timothy R. Walsh, <a href="http://dx.doi.org/10.1137/0604018">Generating nonisomorphic maps without storing them</a>, SIAM J. Algebraic Discrete Methods 4 (1983), no. 2, 161178.
%K nonn,more
%O 3,3
%A _N. J. A. Sloane_
%E a(11) and a(12) from _Sean A. Irvine_, Mar 30 2017
