A120991 - OEIS

A120991

Number of free hexagonal polygons of symmetry class C_(2v) and area n.

0, 0, 1, 1, 9, 12, 39, 61, 178, 274, 796, 1251, 3578, 5692, 16290, 26069, 74980, 120676, 348564, 563503, 1635175, 2652445, 7729807, 12574028, 36784467, 59975232, 176063801, 287613473, 846967739, 1385815492, 4092516853, 6705360813, 19852731854, 32565589836, 96642900684

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OFFSET

1,5

LINKS

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

Markus Vöge, 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 column C_(2c) [sic. This is a typo, should be C_(2v) instead].

CROSSREFS

Sequence in context: A216297 A024312 A024877 * A253088 A341208 A328120

Adjacent sequences: A120988 A120989 A120990 * A120992 A120993 A120994

KEYWORD

nonn

AUTHOR

Parthasarathy Nambi, Aug 19 2006

EXTENSIONS

More terms from N. J. A. Sloane, Aug 27 2006

Name corrected by Andrey Zabolotskiy, Nov 10 2023

STATUS

approved