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A044049 Catafusenes (see reference for precise definition). 0
0, 0, 1, 7, 31, 139, 609, 2677, 11827, 52648, 236071, 1065774, 4841428, 22115678, 101531221, 468224323, 2168076055, 10076177264, 46986612235, 219777649588, 1030892581741, 4848039893338, 22853638285655, 107970202258065 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

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..23.

FORMULA

G.f.=[U(z)+V(z)+U(z)^2+U(z^2)-U(z^2)V(z)+V(z^3)]/2 + [U(z)^3-U(z^3)]/6 - V(z)/z + 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. (26)-(29) of the Cyvin et al. paper). - Emeric Deutsch, May 02 2004

CROSSREFS

Sequence in context: A282857 A296573 A180147 * A255284 A005825 A086901

Adjacent sequences:  A044046 A044047 A044048 * A044050 A044051 A044052

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Emeric Deutsch, May 02 2004

STATUS

approved

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Last modified October 17 04:09 EDT 2019. Contains 328106 sequences. (Running on oeis4.)