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 A003426 Number of stable trees with n nodes. (Formerly M1142) 3
 1, 1, 1, 1, 2, 4, 8, 17, 37, 85, 196, 469, 1134, 2799, 6975, 17628, 44903, 115497, 299089, 780036, 2045924, 5396078, 14299878, 38067356, 101748748, 272995157, 735004112, 1985356350, 5378958683, 14614641597, 39813346977, 108730631236, 297641593852 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Sean A. Irvine and Alois P. Heinz, Table of n, a(n) for n = 1..1000 (first 100 terms from Sean A. Irvine) D. D. Grant, The stability index of graphs, pp. 29-52 of Combinatorial Mathematics (Proceedings 2nd Australian Conf.), Lect. Notes Math. 403, 1974. Gives first 45 terms. K. L. McAvaney, Counting stable trees, pp. 79-85 of Combinatorial Mathematics (Proceedings 2nd Australian Conf.), Lect. Notes Math. 403, 1974. FORMULA a(n) = A000055(n) - A002988(n) + [n <= 2]. - Sean A. Irvine, Feb 13 2016 G.f.: t(x) - b(x) + x + x^2 where t(x) is the g.f. for A000055 and b(x) is the g.f. for A002988. - Sean A. Irvine, Feb 13 2016 CROSSREFS Cf. A006544 (forests). Sequence in context: A004148 A292460 A085022 * A179476 A087803 A212658 Adjacent sequences:  A003423 A003424 A003425 * A003427 A003428 A003429 KEYWORD nonn AUTHOR EXTENSIONS More terms from Sean A. Irvine, Feb 13 2016 STATUS approved

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Last modified October 16 08:03 EDT 2018. Contains 316259 sequences. (Running on oeis4.)