%I A000107 M1442 N0570
%S A000107 0,1,2,5,13,35,95,262,727,2033,5714,16136,45733,130046,370803,
%T A000107 1059838,3035591,8710736,25036934,72069134,207727501,599461094,
%U A000107 1731818878,5008149658,14496034714,41993925955,121747732406
%N A000107 Number of rooted trees with n nodes and a single labeled node; pointed 
               rooted trees; vertebrates.
%D A000107 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A000107 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A000107 J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 
               134.
%D A000107 F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like 
               Structures, Camb. 1998, p. 61, 62 (2.1.8-2.1.10)
%H A000107 T. D. Noe, <a href="b000107.txt">Table of n, a(n) for n=0..200</a>
%H A000107 INRIA Algorithms Project, <a href="http://algo.inria.fr/bin/encyclopedia?Search=ECSnb&argsearch=123">
               Encyclopedia of Combinatorial Structures 123</a>
%H A000107 N. J. A. Sloane, <a href="transforms.txt">Transforms</a>
%H A000107 <a href="Sindx_Ro.html#rooted">Index entries for sequences related to 
               rooted trees</a>
%H A000107 <a href="Sindx_Tra.html#trees">Index entries for sequences related to 
               trees</a>
%p A000107 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]
%Y A000107 INVERT transform of A000081. Cf. A000243, A000269, A000312, A000444, 
               A000485, A000524-A000526.
%Y A000107 Sequence in context: A024576 A057960 A007075 this_sequence A063028 A085810 
               A005773
%Y A000107 Adjacent sequences: A000104 A000105 A000106 this_sequence A000108 A000109 
               A000110
%K A000107 nonn,easy,nice
%O A000107 0,3
%A A000107 N. J. A. Sloane (njas(AT)research.att.com).
%E A000107 Better description from Christian G. Bower (bowerc(AT)usa.net), Apr 15 
               1998.