%I M1238 #19 Mar 29 2017 03:12:14
%S 1,2,4,10,36,132,616,3060,16207,88990,503816
%N Number of planar maps with n edges and without faces or 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, 161-178.
%K nonn,more
%O 2,2
%A _N. J. A. Sloane_
%E a(9)-a(12) from _Sean A. Irvine_, Mar 28 2017