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

 

Logo

Many excellent designs for a new banner were submitted. We will use the best of them in rotation.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A107917 (1/86400)(n+1)(n+2)^2*(n+3)^3*(n+4)^2*(n+5)(n^2+6n+10). 2
1, 34, 455, 3626, 20580, 91728, 340956, 1099890, 3166449, 8302294, 20131111, 45677996, 97894160, 199645824, 389817072, 732389580, 1329624009, 2340785370, 4008235231, 6693165094, 10923775940, 17459327600, 27374197500, 42166911150, 63900046665, 95377983246 (list; graph; refs; listen; history; text; 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).

LINKS

T. D. Noe, Table of n, a(n) for n = 0..1000

FORMULA

Empirical G.f.: (x^6+22*x^5+113*x^4+190*x^3+113*x^2+22*x+1)/(x-1)^12. [Colin Barker, Jun 06 2012]

MAPLE

a:=n->(1/86400)*(n+1)*(n+2)^2*(n+3)^3*(n+4)^2*(n+5)*(n^2+6*n+10): seq(a(n), n=0..27);

CROSSREFS

Sequence in context: A033914 A189452 A159655 * A066291 A228682 A020929

Adjacent sequences:  A107914 A107915 A107916 * A107918 A107919 A107920

KEYWORD

nonn,easy

AUTHOR

Emeric Deutsch, Jun 12 2005

STATUS

approved

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

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

Last modified April 18 19:33 EDT 2014. Contains 240733 sequences.