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A044047 Catafusenes (see reference for precise definition). 0
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; text; internal format)
OFFSET

0,5

LINKS

Table of n, a(n) for n=0..24.

S. J. Cyvin et al., Enumeration and Classification of Certain Polygonal Systems Representing Polycyclic Conjugated Hydrocarbons: Annelated Catafusenes, J. Chem. Inform. Comput. Sci., 34 (1994), 1174-1180.

F. Harary and R. C. Read, The enumeration of tree-like polyhexes, Proc. Edinburgh Math. Soc. (2) 17 (1970), 1-13.

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).

CROSSREFS

Sequence in context: A247121 A078543 A084128 * A296944 A105487 A098453

Adjacent sequences:  A044044 A044045 A044046 * A044048 A044049 A044050

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Emeric Deutsch, Mar 14 2004

STATUS

approved

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Last modified September 20 07:32 EDT 2021. Contains 347577 sequences. (Running on oeis4.)