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A044047
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Catafusenes (see reference for precise definition).
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0
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0, 0, 0, 1, 2, 12, 56, 282, 1365, 6666, 32002, 153350, 731156, 3480594, 16546884, 78644579, 373813930, 1777680136, 8459543997, 40290717546, 192072529566, 916541991433, 4378019950311, 20933668637794, 100196639221232
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,5
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REFERENCES
| S. J. Cyvin et al., Enumeration and classification of certain polygonal systems...: annelated catafusenes, J. Chem. Inform. Comput. Sci., 34 (1994), 1174-1180.
F. Harary and R. C. Read, The enumeration of tree-like polyhexes, Proc. Edinb. Math. Soc. (2) 17 (1970), 1-13.
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FORMULA
| G.f. = (1/2)U(z^2)V(z)+(1/6)U(z)^3+(1/3)U(z^3) 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)] (eq. (26) in the Cyvin et al. paper).
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CROSSREFS
| Sequence in context: A181298 A078543 A084128 * A105487 A098453 A180073
Adjacent sequences: A044044 A044045 A044046 * A044048 A044049 A044050
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 14 2004
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