login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 (list; graph; refs; listen; history; text; internal format)
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.

LINKS

Table of n, a(n) for n=52..63.

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: A033856 A143861 A100174 * A062022 A277986 A261282

Adjacent sequences:  A120368 A120369 A120370 * A120372 A120373 A120374

KEYWORD

nonn

AUTHOR

Parthasarathy Nambi, Aug 27 2006

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 5 11:57 EST 2021. Contains 341823 sequences. (Running on oeis4.)