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Number of bipartite 2-connected outerplanar graphs on n unlabeled nodes.
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%I #12 Feb 12 2021 20:08:03

%S 0,1,0,1,0,2,0,4,0,13,0,48,0,238,0,1325,0,8297,0,54519,0,373363,0,

%T 2621872,0,18797682,0,136969519,0,1011903735,0,7564219361,0,

%U 57129086391,0,435394899361,0,3345082819597,0,25885718422329,0,201619294539406,0,1579629974876090

%N Number of bipartite 2-connected outerplanar graphs on n unlabeled nodes.

%C Also the number of bipartite (unlabeled) dissections of a polygon.

%H M. Bordirsky, É. Fusy, M. Kang and S. Vigerske, <a href="http://www.arXiv.org/abs/math.CO/0511422">Enumeration of Unlabeled Outerplanar Graphs</a>, 2005

%H S. Vigerske, <a href="http://www.informatik.hu-berlin.de/Forschung_Lehre/algorithmen/en/forschung/planar/vigerske.html">Asymptotic enumeration of unlabeled outerplanar graphs, Diploma thesis</a>, Humboldt University Berlin, 2005

%H S. Vigerske, <a href="http://www.math.hu-berlin.de/~stefan">Homepage</a>

%F Generating function and cycle index sum known, see Vigerske.

%o (PARI) \\ See A295419 for DissectionsModDihedral.

%o {my(N=50); DissectionsModDihedral(vector(N, n, n%2==0)) + vector(N, n, n==2)} \\ _Andrew Howroyd_, Feb 12 2021

%Y Even bisection gives A290722.

%Y Cf. A001004, A111758, A111759, A295419.

%K nonn

%O 1,6

%A Stefan Vigerske, Nov 21 2005

%E Terms a(21) and beyond from _Andrew Howroyd_, Feb 12 2021