Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A120991
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A120991 Number of free hexagonal polygons of symmetry class C_(2c) and area n. +0
2
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 (list; graph; listen)
OFFSET

1,5

REFERENCES

Markus Voege, 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 C_(2c) column.

EXAMPLE

If n=10 then the number of free hexagonal polygons of symmetry class C_(2c) is 274 which is the tenth term in the sequence.

CROSSREFS

Adjacent sequences: A120988 A120989 A120990 this_sequence A120992 A120993 A120994

Sequence in context: A105704 A024312 A024877 this_sequence A072308 A045769 A140145

KEYWORD

nonn

AUTHOR

Parthasarathy Nambi (PachaNambi(AT)yahoo.com), Aug 19 2006

EXTENSIONS

More terms from njas, Aug 27 2006

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified October 12 11:54 EDT 2008. Contains 144829 sequences.


AT&T Labs Research