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A121212
Number of free hexagonal polygons of symmetry class C_(3h) and area n.
1
0, 0, 0, 0, 0, 1, 1, 0, 5, 5, 0, 21, 26, 0, 95, 118, 0, 423, 543, 0, 1923, 2507, 0, 8869, 11676, 0, 41410, 54893, 0, 195353, 260220, 0, 929423, 1242820, 0
OFFSET
1,9
REFERENCES
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 C_(3h) column.
CROSSREFS
Sequence in context: A233383 A144184 A119380 * A182787 A133337 A279932
KEYWORD
nonn
AUTHOR
Parthasarathy Nambi, Aug 19 2006
STATUS
approved