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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 (list; graph; refs; listen; history; text; internal format)
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.

LINKS

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

CROSSREFS

Sequence in context: A233383 A144184 A119380 * A182787 A133337 A279932

Adjacent sequences:  A121209 A121210 A121211 * A121213 A121214 A121215

KEYWORD

nonn

AUTHOR

Parthasarathy Nambi, Aug 19 2006

STATUS

approved

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Last modified December 11 22:04 EST 2018. Contains 318052 sequences. (Running on oeis4.)