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Search: id:A000357
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| A000357 |
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Number of 5-level labeled rooted trees with n leaves.
(Formerly M3979 N1648)
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+0
16
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| 1, 1, 5, 35, 315, 3455, 44590, 660665, 11035095, 204904830, 4183174520, 93055783320, 2238954627848, 57903797748386, 1601122732128779, 47120734323344439, 1470076408565099152, 48449426629560437576
(list; graph; listen)
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OFFSET
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0,3
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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).
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
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.
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LINKS
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Index entries for sequences related to rooted trees
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 294
Gottfried Helms, Bell Numbers, 2008.
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FORMULA
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E.g.f.: exp(exp(exp(exp(exp(x)-1)-1)-1)-1).
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MAPLE
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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(1)))): seq (a(n), n=0..30); [From Alois P. Heinz (heinz(AT)hs-heilbronn.de), Sep 11 2008]
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CROSSREFS
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a(n)=|A039813(n, 1)| (first column of triangle). Cf. A000110, A000258, A000307, A000405, A001669.
Sequence in context: A052797 A151344 A015683 this_sequence A051577 A102147 A124564
Adjacent sequences: A000354 A000355 A000356 this_sequence A000358 A000359 A000360
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KEYWORD
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nonn,easy
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
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Extended with new description by Christian G. Bower (bowerc(AT)usa.net), Aug 15 1998.
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