A044044 Catafusenes (see reference for precise definition).

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.

Links

Table of n, a(n) for n=0..32.

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

Adjacent sequences: A044041 A044042 A044043 * A044045 A044046 A044047

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Emeric Deutsch, May 02 2004

Status

approved