%I A002707 M3128 N1268
%S A002707 1,1,3,31,8401,100130704103,167321084032306100365838018661441,
%T A002707 780729803567659232170209385771412393899822868427528396719062233553621064241305757906662806984051
%N A002707 Number of ternary trees with n nodes.
%D A002707 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A002707 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A002707 Z. A. Melzak, A note on homogeneous dendrites, Canad. Math. Bull., 11 
               (1968), 85-93.
%H A002707 <a href="Sindx_Tra.html#trees">Index entries for sequences related to 
               trees</a>
%F A002707 a(n) = a(n-1)*(a(n-1)+a(n-2))*(a(n-1)+a(n-2)+a(n-3))/6 + a(n-1)*(a(n-1)+a(n-2))/
               (a(n-2)+a(n-3))*(a(n-1)/a(n-2)-a(n-2)/a(n-3)) + a(n-1)^2/a(n-2).
%Y A002707 Sequence in context: A022499 A129209 A134721 this_sequence A144964 A118913 
               A005042
%Y A002707 Adjacent sequences: A002704 A002705 A002706 this_sequence A002708 A002709 
               A002710
%K A002707 nonn,nice,easy
%O A002707 0,3
%A A002707 N. J. A. Sloane (njas(AT)research.att.com).
%E A002707 More terms and recurrence from James A. Sellers (sellersj(AT)math.psu.edu), 
               Feb 14 2000