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Number of benzenoids with 21 hexagons with D_(2h) symmetry and 60+2n carbons.
31

%I #9 Nov 15 2023 13:14:08

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

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

%C 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

%H G. Brinkmann, G. Caporossi and P. Hansen, <a href="https://doi.org/10.1021/ci025526c">A survey and new results on computer enumeration of polyhex and fusene hydrocarbons</a>, J. Chem. Inf. Comput. Sci., vol. 43 (2003) pp. 842-851. See Table 4 column 5 on page 846.

%e 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.

%K nonn,fini,full

%O 0,2

%A _Parthasarathy Nambi_, Sep 18 2006

%E Edited by _R. J. Mathar_, May 02 2008

%E Follow-up edits by _Andrey Zabolotskiy_, Nov 10 2023