1,4

Markus Voege, Anthony J. Guttmann and Iwan Jensen, "On the number of benzenoid hydrocarbons", J. Chem. Inf. Comput. Sci., (2002), vol. 42, 456-466. See Table 3 under the D_(2h) column.

Table of n, a(n) for n=1..35.

If n=10 then the number of free hexagonal polygons of symmetry class D_(2h) is 11 which is the tenth term in the sequence.

Sequence in context: A116450 A054172 A236971 * A316585 A146157 A238363

Adjacent sequences: A121208 A121209 A121210 * A121212 A121213 A121214

nonn

Parthasarathy Nambi, Aug 19 2006

approved