A006401 - OEIS

%I M1384 #22 Jan 16 2025 16:20:29

%S 1,0,0,1,1,2,5,10,28,86,285,1055,4211

%N Number of unsensed simple planar maps with n edges and without vertices of degree 1.

%C A simple planar map is a planar map without loops or parallel edges. - _Andrew Howroyd_, Jan 16 2025

%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.

%Y Cf. A006385, A006389, A006395, A006400 (sensed), A379436 (rooted).

%K nonn,more

%O 0,6

%A _N. J. A. Sloane_

%E a(11)-a(12) from _Sean A. Irvine_, Mar 31 2017

%E a(0)-a(2) prepended by _Andrew Howroyd_, Jan 16 2025