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 A006573 Denominators of an asymptotic expansion for the number of forests on n nodes (A001858). (Formerly M1828) 3
 1, 1, 1, 2, 8, 16, 384, 768, 3072, 6144, 1474560, 589824, 11796480, 7864320, 11890851840, 23781703680, 95126814720, 27179089920, 91321742131200, 7305739370496, 730573937049600, 1461147874099200, 385743038762188800, 771486077524377600 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS Takacs Table 2 gives incorrect A006572(10)/A006573(10) = -137483257/61440 and A006572(11)/A006573(11) = -24971924401/983040. - Sean A. Irvine, May 11 2017 REFERENCES 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. LINKS FORMULA 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 CROSSREFS Cf. A006572, A001858, A111999. Sequence in context: A101059 A191999 A101658 * A009662 A279243 A162218 Adjacent sequences:  A006570 A006571 A006572 * A006574 A006575 A006576 KEYWORD nonn,frac AUTHOR EXTENSIONS a(10) and a(11) corrected and more terms from Sean A. Irvine, May 11 2017 STATUS approved

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Last modified October 16 05:44 EDT 2018. Contains 316259 sequences. (Running on oeis4.)