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Search: id:A000107
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| A000107 |
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Number of rooted trees with n nodes and a single labeled node; pointed rooted trees; vertebrates.
(Formerly M1442 N0570)
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+0
14
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| 0, 1, 2, 5, 13, 35, 95, 262, 727, 2033, 5714, 16136, 45733, 130046, 370803, 1059838, 3035591, 8710736, 25036934, 72069134, 207727501, 599461094, 1731818878, 5008149658, 14496034714, 41993925955, 121747732406
(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. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 134.
F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like Structures, Camb. 1998, p. 61, 62 (2.1.8-2.1.10)
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LINKS
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T. D. Noe, Table of n, a(n) for n=0..200
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 123
N. J. A. Sloane, Transforms
Index entries for sequences related to rooted trees
Index entries for sequences related to trees
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MAPLE
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with (numtheory): b:= proc(n) option remember; `if` (n<2, n, add (add (d*b(d), d=divisors(j)) *b(n-j), j=1..n-1) /(n-1)) end: a:= proc(n) option remember; b(n) +add (a(n-i) *b(i), i=1..n-1) end: seq (a(n), n=0..26); [From Alois P. Heinz (heinz(AT)hs-heilbronn.de), Jun 02 2009]
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CROSSREFS
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INVERT transform of A000081. Cf. A000243, A000269, A000312, A000444, A000485, A000524-A000526.
Sequence in context: A024576 A057960 A007075 this_sequence A063028 A085810 A005773
Adjacent sequences: A000104 A000105 A000106 this_sequence A000108 A000109 A000110
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KEYWORD
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nonn,easy,nice
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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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Better description from Christian G. Bower (bowerc(AT)usa.net), Apr 15 1998.
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