%I #9 Mar 08 2020 03:36:54
%S 0,1,1,4,6,15,25,57,103,223,417,898,1722,3707,7211,15620,30724,66939,
%T 132729,290916,580680,1279281,2567397,5682009,11456481,25454265,
%U 51528969,114880470,233380592,521860455,1063460261,2384247105
%N Catafusenes (see reference for precise definition).
%D S. J. Cyvin et al., Enumeration and classification of certain polygonal systems... : annelated catafusenes, J. Chem. Inform. Comput. Sci., 34 (1994), 1174-1180.
%F G.f. = V(z) + (U(z^2) + V(z)^2 - V(z^2)^2 + U(z^2)V(z)^2)/2 - V(z^2) + U(z^2)V(z), where U(z) = (1 - 3z - sqrt(1-6z + 5z^2))/(2z) and V(z) = (1 - z^2 - sqrt(1-6z^2+5z^4))/(2z(1-z)) (from eq. (54) of the Cyvin et al. paper). - _Emeric Deutsch_, May 02 2004
%K nonn
%O 0,4
%A _N. J. A. Sloane_
%E More terms from _Emeric Deutsch_, May 02 2004
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