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A044044
Catafusenes (see reference for precise definition).
0
0, 1, 2, 2, 6, 10, 19, 36, 72, 135, 274, 543, 1084, 2219, 4438, 9280, 18570, 39587, 79169, 171369, 342738, 751221, 1502472, 3328218, 6656421, 14878455, 29756910, 67030734, 134061570, 304036170, 608072289, 1387247580, 2774495160
OFFSET
0,3
REFERENCES
S. J. Cyvin et al., Enumeration and classification of certain polygonal systems...: annelated catafusenes, J. Chem. Inform. Comput. Sci., 34 (1994), 1174-1180.
FORMULA
G.f.: U(z^2)*V(z) + V(z)/z - V(z^3) - 1, where U(z) = (1 - 3*z - sqrt(1-6*z+ 5*z^2)) / (2*z) and V(z) = (1 - z^2 - sqrt(1-6*z^2+5*z^4)) / (2*z*(1-z)) (from eq. (29) of the Cyvin et al. paper). - Emeric Deutsch, May 02 2004
CROSSREFS
Cf. A002212 (U), A055879 (V).
Sequence in context: A165941 A054227 A054228 * A123757 A167399 A247326
KEYWORD
nonn
EXTENSIONS
More terms from Emeric Deutsch, May 02 2004
STATUS
approved