A122539 Number of benzenoids with 21 hexagons with D_(2h) symmetry and 60+2n carbons.

1, 3, 5, 8, 12, 16, 16, 42, 31, 43, 45, 73, 30, 40

Offset

0,2

Comments

The total number of carbons in 21 free hexagons is 6*21=126, but since they have to be attached (form overlapping molecules sharing edges) the sequence ends already at compounds with 86 carbons. - R. J. Mathar, May 02 2008

Links

Table of n, a(n) for n=0..13.

G. Brinkmann, G. Caporossi and P. Hansen, A survey and new results on computer enumeration of polyhex and fusene hydrocarbons, J. Chem. Inf. Comput. Sci., vol. 43 (2003) pp. 842-851. See Table 4 column 5 on page 846.

Example

For n=10, there are 16 different forms of C_70H_30 of benzenoids of 21 hexagons attached along at least one edge, which each have D_(2h) planar symmetry.

Crossrefs

Sequence in context: A310030 A045716 A236203 * A310031 A310032 A310033

Adjacent sequences: A122536 A122537 A122538 * A122540 A122541 A122542

Keyword

nonn,fini,full

Author

Parthasarathy Nambi, Sep 18 2006

Extensions

Edited by R. J. Mathar, May 02 2008

Follow-up edits by Andrey Zabolotskiy, Nov 10 2023

Status

approved