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A036671
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Number of isomers C_n H_{2n} without double bonds.
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8
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0, 0, 1, 2, 5, 12, 29, 73, 185, 475, 1231, 3232, 8506, 22565, 60077, 160629, 430724, 1158502, 3122949, 8437289, 22836877, 61918923, 168139339, 457225555, 1244935251, 3393754661, 9261681937, 25301337669, 69184724389, 189349490641
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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COMMENTS
| Apparently the same as the number of simple graphs with n vertices and one cycle - see table 1 in Michael A. Kappler reference. - Jonathan Vos Post (jvospost3(AT)gmail.com.com), Dec 07 2005
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REFERENCES
| Camden A. Parks and James B. Hendrickson, Enumeration of monocyclic and bicyclic carbon skeletons, J. Chem. Inf. Comput. Sci., vol. 31, 334-339 (1991). See page 335 Table 1.
G. Polya, Kombinatorische Anzahlbestimmungen fuer Gruppen, Graphen und chemische Verbindungen, Acta Math. 68 (1937), 145-254, see p. 227.
J. B. Hendrikson and C. A. Parks, "Generation and Enumeration of Carbon skeletons", J. Chem. Inf. Comput. Sci, vol. 31 (1991) pp. 101-107. See Table 2, column 3 on page 103.
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LINKS
| Michael A. Kappler, GENSMI: Exhaustive Enumeration of Simple Graphs.
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FORMULA
| Polya reference gives an explicit g.f.; so does Parks et al.
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CROSSREFS
| Cf. A000598, A000642.
Sequence in context: A010374 A025273 A089372 * A152171 A132807 A101411
Adjacent sequences: A036668 A036669 A036670 * A036672 A036673 A036674
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KEYWORD
| nonn,easy
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Aug 19 2001
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