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A001863
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Normalized total height of rooted trees with n nodes.
(Formerly M3614 N1466)
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5
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0, 1, 4, 26, 236, 2760, 39572, 672592, 13227804, 295579520, 7398318500, 205075286784, 6236796259916, 206489747516416, 7393749269685300
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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REFERENCES
| N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
| T. D. Noe, Table of n, a(n) for n=1..100
J. Riordan and N. J. A. Sloane, Enumeration of rooted trees by total height, J. Austral. Math. Soc., vol. 10 pp. 278-282, 1969.
Index entries for sequences related to rooted trees
Index entries for sequences related to trees
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FORMULA
| E.g.f.: -exp(1)*x*(Ei(-1-LambertW(-x))-Ei(-1))-LambertW(-x)+ln(1+LambertW(-x)). - Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 29 2003
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MAPLE
| A001863 := n->sum((n-2)!*n^k/k!, k=0..n-2); #for n>1. Equals A001864/(n^2-n)
seq(simplify(GAMMA(n-1, n)*exp(n)), n=2..20); (Vladeta Jovovic (vladeta(AT)eunet.rs), Jul 21 2005)
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CROSSREFS
| Cf. A000435, A001864.
Sequence in context: A054360 A124824 A000311 * A115416 A052577 A203935
Adjacent sequences: A001860 A001861 A001862 * A001864 A001865 A001866
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KEYWORD
| nonn,nice,easy
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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