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A035088
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Number of labeled polygonal cacti (Husimi graphs) with n nodes.
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3
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1, 1, 0, 1, 3, 27, 240, 2985, 42840, 731745, 14243040, 313570845, 7683984000, 207685374435, 6135743053440, 196754537704725, 6805907485977600, 252620143716765825
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,5
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COMMENTS
| A Husimi tree is a connected graph in which no line lies on more than one cycle [Harary, 1953]. [From Jonathan Vos Post (jvospost3(AT)gmail.com), Mar 12 2010]
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REFERENCES
| F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like Structures, Camb. 1998, p. 301.
F. Harary and R. Z. Norman "The Dissimilarity Characteristic of Husimi Trees" Annals of Mathematics, 58 1953, pp. 134-141
F. Harary and E. M. Palmer, Graphical Enumeration, p. 71
F. Harary and G. E. Uhlenbeck "On the Number of Husimi Trees" Proc. Nat. Acad. Sci. USA vol. 39 pp. 315-322 1953
Harary, F.; Uhlenbeck, G. (1953), "On the number of Husimi trees, I", Proceedings of the National Academy of Sciences 39: 315-322. [From Jonathan Vos Post (jvospost3(AT)gmail.com), Mar 12 2010]
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LINKS
| Index entries for sequences related to cacti
Index entries for sequences related to trees
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FORMULA
| A035087/n, n>0.
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CROSSREFS
| Cf. A035082-A035087.
Sequence in context: A145608 A083713 A065100 * A013708 A102518 A074117
Adjacent sequences: A035085 A035086 A035087 * A035089 A035090 A035091
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KEYWORD
| nonn,nice
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AUTHOR
| Christian G. Bower (bowerc(AT)usa.net), Nov 15 1998
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