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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 (list; graph; refs; listen; history; text; internal format)
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)=[1-3z-sqrt(1-6z+ 5z^2)]/(2z) and V(z)=[1-z^2-sqrt(1-6z^2+5z^4)]/[2z(1-z)] (from eq. (29) of the Cyvin et al. paper). - Emeric Deutsch, May 02 2004

CROSSREFS

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

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Last modified January 20 13:18 EST 2021. Contains 340302 sequences. (Running on oeis4.)