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A006573
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Denominators of an asymptotic expansion for the number of forests on n nodes (A001858).
(Formerly M1828)
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3
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1, 1, 1, 2, 8, 16, 384, 768, 3072, 6144, 1474560, 589824, 11796480, 7864320, 11890851840, 23781703680, 95126814720, 27179089920, 91321742131200, 7305739370496, 730573937049600, 1461147874099200, 385743038762188800, 771486077524377600
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OFFSET
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0,4
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COMMENTS
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
L. Takacs, On the number of distinct forests, SIAM J. Discrete Math., 3 (1990), 574-581.
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LINKS
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FORMULA
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a(n) = denom(Sum_{i=1..floor(n/2)} (-1)^(i-1) * |A111999(n, 2*i-1)| / (2^(n-i) * (n-i)!)). - Sean A. Irvine, May 11 2017
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CROSSREFS
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KEYWORD
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nonn,frac
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AUTHOR
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EXTENSIONS
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a(10) and a(11) corrected and more terms from Sean A. Irvine, May 11 2017
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STATUS
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approved
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