%I A006078 M3822
%S A006078 1,1,5,12,45,143,511,1768,6330,22610,81818,297160,1086813,3991995,
%T A006078 14733435,54587280,203000094,757398510,2834519142,10637507400,
%U A006078 40023665682,150946230006,570534682710,2160865067312,8199711750100
%N A006078 Number of triangulated (n+2)-gons rooted at an exterior edge.
%D A006078 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A006078 S. J. Cyvin, J. Brunvoll, E. Brendsdal, B. N. Cyvin and E. K. Lloyd, 
               Enumeration of polyene hydrocarbons: a complete mathematical solution, 
               J. Chem. Inf. Comput. Sci., 35 (1995) 743-751
%D A006078 P. K. Stockmeyer, The charm bracelet problem and its applications, pp. 
               339-349 of Graphs and Combinatorics (Washington, Jun 1973), Ed. by 
               R. A. Bari and F. Harary. Lect. Notes Math., Vol. 406. Springer-Verlag, 
               1974.
%F A006078 Stockmeyer gives a g.f.
%F A006078 G.f.=[4(1-x-x^2)-(1-2x)(1-4x)^(1/2)-3(1-4x^2)^(1/2)]/(8x^2). - Emeric 
               Deutsch (deutsch(AT)duke.poly.edu), Dec 19 2004
%p A006078 G:=(4*(1-x-x^2)-(1-2*x)*(1-4*x)^(1/2)-3*(1-4*x^2)^(1/2))/8/x^2: Gser:=series(G,
               x=0,35): seq(coeff(Gser,x^n),n=2..28); (Deutsch)
%Y A006078 Sequence in context: A129795 A052644 A052280 this_sequence A046612 A009425 
               A009416
%Y A006078 Adjacent sequences: A006075 A006076 A006077 this_sequence A006079 A006080 
               A006081
%K A006078 nonn,easy,nice
%O A006078 2,3
%A A006078 N. J. A. Sloane (njas(AT)research.att.com), E. K. Lloyd (E.K.Lloyd(AT)soton.ac.uk)
%E A006078 More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Dec 19 2004