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A001669
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Number of 7-level labeled rooted trees with n leaves.
(Formerly M4443 N1879)
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12
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1, 1, 7, 70, 910, 14532, 274778, 5995892, 148154860, 4085619622, 124304629050, 4133867297490, 149114120602860, 5796433459664946, 241482353893283349, 10730629952953517859, 506500241174366575122, 25302666611855946733140
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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REFERENCES
| J. Ginsburg, Iterated exponentials, Scripta Math., 11 (1945), 340-353.
T. Hogg and B. A. Huberman, Attractors on finite sets: the dissipative dynamics of computing structures, Phys. Review A 32 (1985), 2338-2346.
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
| P. J. Cameron, Sequences realized by oligomorphic permutation groups, J. Integ. Seqs. Vol. 3 (2000), #00.1.5.
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 296
Index entries for sequences related to rooted trees
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FORMULA
| E.g.f.: exp(exp(exp(exp(exp(exp(exp(x)-1)-1)-1)-1)-1)-1).
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MAPLE
| g:= proc(p) local b; b:= proc(n) option remember; if n=0 then 1 else (n-1)! *add (p(k)*b(n-k)/ (k-1)!/ (n-k)!, k=1..n) fi end end: a:= g(g(g(g(g(g(1)))))): seq (a(n), n=0..30); # Alois P. Heinz, Sep 11 2008
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CROSSREFS
| Cf. A000110, A000258, A000307, A000357, A000405.
Sequence in context: A113343 A124566 A141151 * A051604 A097630 A090647
Adjacent sequences: A001666 A001667 A001668 * A001670 A001671 A001672
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KEYWORD
| nonn,easy
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| Extended with new definition by Christian G. Bower (bowerc(AT)usa.net), Aug 15 1998.
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