%I A018190
%S A018190 1,1,3,7,22,81,331,1435,6505,30086,141229,669584,3198256,15367577,
%T A018190 74207910,359863778,1751594643,8553649747,41892642772,205714411986,
%U A018190 1012565172403,4994807695197,24687124900540,122238208783203
%N A018190 Number of planar simply-connected polyhexes (or benzenoid hydrocarbons) 
               with n hexagons.
%D A018190 Gunnar Brinkmann, Gilles Caporossi and Pierre Hansen, A constructive 
               enumeration of fusenes and benzenoids, Journal of Algorithms 45 (2002), 
               pp. 155-166.
%D A018190 Gunnar Brinkmann, Gilles Caporossi and Pierre Hansen, A survey and new 
               results on computer enumeration of polyhex and fusene hydrocarbons, 
               J. Chem. Inf. Comput. Sci., 43 (2003), 842-851.
%D A018190 J. Brunvoll et al., Studies of some chemically relevant polygonal systems: 
               mono-q-polyhexes, ACH Models in Chem., 133 (3) (1996), 277-298.
%D A018190 J. L. Faulon, D. Visco and D. Roe, Enumerating Molecules, In: Reviews 
               in Computational Chemistry Vol. 21, Ed. K. Lipkowitz, Wiley-VCH, 
               2005.
%D A018190 J. V. Knop et al., On the total number of polyhexes, Match, No. 16 (1984), 
               119-134.
%D A018190 J. V. Knop et al., Use of small computers for large computations..., 
               J. Chem. Inf. Comput. Sci., 30 (1990), 159-160.
%D A018190 E. V. Konstantinova and M. V. Vidyuk, Discriminating tests of information 
               and toplogical indices; animals and trees; J. Chem. Inf. Comput. 
               Sci., 43 (2003), 1860-1871.
%D A018190 S. Nikolic et al., On the concept of the weighted spanning tree of dualist, 
               J. Math. Chem. 4 (1990), 357-375.
%D A018190 Tosic R., Masulovic D., Stojmenovic I., Brunvoll J., Cyvin B. N. and 
               Cyvin S. J., Enumeration of polyhex hydrocarbons to h = 17, J. Chem. 
               Inf. Comput. Sci., 1995, 35, 181-187.
%D A018190 N. Trinajstich, Z. Jerievi, J. V. Knop, W. R. Muller and K. Szymanski, 
               COMPUTER GENERATION OF ISOMERIC STRUCTURES, Pure & Appl. Chem., Vol. 
               55, No. 2, pp. 379-39O, 1983.
%D A018190 Markus Voege, Anthony J. Guttmann and Iwan Jensen, On the Number of Benzenoid 
               Hydrocarbons, Journal of Chemical Information and Computer Sciences, 
               42(3) (2002), 456-466.
%D A018190 G. Caporossi and P. Hansen, "Enumeration of polyhex hydrocarbons to h=21", 
               J. Chem. Inf. Comput. Sci., vol. 38 (1998), pp. 610-619
%H A018190 N. J. A. Sloane, <a href="b018190.txt">Table of n, a(n) for n = 1..35</
               a> [from Voege et al.]
%H A018190 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Polyhex.html">Link to a section of The World of Mathematics.</a>
%H A018190 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Benzenoid.html">Benzenoid</a>
%H A018190 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Fusene.html">Fusene</a>
%Y A018190 Cf. A000228, A002216, A018190, A038142-A038147.
%Y A018190 Sequence in context: A075214 A070766 A111772 this_sequence A000228 A108070 
               A038147
%Y A018190 Adjacent sequences: A018187 A018188 A018189 this_sequence A018191 A018192 
               A018193
%K A018190 nonn,nice
%O A018190 1,3
%A A018190 N. J. A. Sloane (njas(AT)research.att.com), Viviane Rochon (viviane(AT)crt.umontreal.ca), 
               Gilles Caporossi (gillesc(AT)crt.umontreal.ca)
%E A018190 More terms from Joseph Myers (jsm(AT)polyomino.org.uk), Nov 06 2003
%E A018190 Further terms added by N. J. A. Sloane (njas(AT)research.att.com) from 
               Brinkmann et al. (2003). Jun 04 2005