login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A107956 (1/2880)(n+1)(n+2)^2*(n+3)^2*(n+4)(5n^2+21n+20). 0
1, 23, 205, 1120, 4508, 14700, 41076, 101970, 230505, 482911, 949949, 1772134, 3159520, 5416880, 8975184, 14430348, 22590297, 34531455, 51665845, 75820052, 109327372, 155134540, 216924500, 299256750, 407726865, 549146871, 731748213 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Kekule numbers for certain benzenoids.

REFERENCES

S. J. Cyvin and I. Gutman, Kekule structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (p. 229).

MAPLE

a:=n->(1/2880)*(n+1)*(n+2)^2*(n+3)^2*(n+4)*(5*n^2+21*n+20): seq(a(n), n=0..30);

CROSSREFS

Sequence in context: A065316 A060882 A128334 * A022683 A042020 A084428

Adjacent sequences:  A107953 A107954 A107955 * A107957 A107958 A107959

KEYWORD

nonn

AUTHOR

Emeric Deutsch (deutsch(AT)duke.poly.edu), Jun 12 2005

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 17:48 EST 2012. Contains 205939 sequences.