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A058862
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Number of chordal labeled graphs (connected or not) with n nodes.
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3
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1, 2, 8, 61, 822, 18154, 617675, 30888596, 2192816760, 215488096587, 28791414081916, 5165908492061926
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OFFSET
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1,2
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REFERENCES
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N. C. Wormald, Counting labeled chordal graphs. Graphs Combin. 1 (1985), no. 2, 193-200.
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LINKS
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Table of n, a(n) for n=1..12.
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FORMULA
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From the relation G(x)=exp(g(x)) between generating functions for connected g(x) and all G(x) labeled structures and considering generating functions for chordal graphs (c_n, A007134), we have a_n = c_n + \frac{1}{n} Sum_{k=1}^{n-1} k {n choose k} c_k a_{n-k}
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CROSSREFS
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Cf. A007134.
Sequence in context: A188489 A085657 A005215 * A191482 A140722 A116976
Adjacent sequences: A058859 A058860 A058861 * A058863 A058864 A058865
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KEYWORD
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nonn,nice
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AUTHOR
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Robert Castelo (rcastelo(AT)imim.es), Jan 06 2001
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STATUS
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approved
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