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A120371
Number of isomers of polyhex hydrocarbons with C_(2h) symmetry with eighteen hexagons.
0
1, 14, 59, 206, 601, 1602, 3832, 8050, 14601, 22472, 24071, 14756
OFFSET
52,2
COMMENTS
See Table 3 column 3 on page 614 of the paper by Caporossi and Hansen. Also the sequence starts for the hydrocarbon C_52H_18. If the number of carbons is an odd number then the number of isomers with this symmetry is zero.
REFERENCES
G. Caporossi and P. Hansen, "Enumeration of Polyhex Hydrocarbons to h=21", J. Chem. Inf. Comput. Sci., vol. 38 (1998) pp. 610-619.
EXAMPLE
If the number of carbons is 54 then the number of isomers of polyhex hydrocarbons with C_(2h) symmetry with eighteen hexagons is 14 which is the third term in the sequence.
CROSSREFS
Cf. A018190.
Sequence in context: A143861 A100174 A372675 * A062022 A277986 A261282
KEYWORD
nonn
AUTHOR
Parthasarathy Nambi, Aug 27 2006
STATUS
approved