|
| |
|
|
A114244
|
|
a(n)=(n+1)(n+2)^2*(n+3)(7n^2+28n+30)/360.
|
|
1
| |
|
|
1, 13, 76, 295, 889, 2254, 5040, 10242, 19305, 34243, 57772, 93457, 145873, 220780, 325312, 468180, 659889, 912969, 1242220, 1664971, 2201353, 2874586, 3711280, 4741750, 6000345, 7525791, 9361548, 11556181, 14163745, 17244184, 20863744
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| Kekule numbers for certain benzenoids.
First differences of A114242. - Peter Bala (pbala(AT)toucansurf.com), Sep 21 2007
|
|
|
REFERENCES
| S. J. Cyvin and I. Gutman, Kekule structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (pp. 167-169, Table 10.5/II/5).
|
|
|
FORMULA
| G.f.=(1+x)(1+5x+x^2)/(1-x)^7.
|
|
|
MAPLE
| a:=n->(n+1)*(n+2)^2*(n+3)*(7*n^2+28*n+30)/360: seq(a(n), n=0..35);
|
|
|
CROSSREFS
| Cf. A114242.
Sequence in context: A051361 A114070 A005340 * A050485 A034265 A060717
Adjacent sequences: A114241 A114242 A114243 * A114245 A114246 A114247
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Emeric Deutsch (deutsch(AT)duke.poly.edu), Nov 18 2005
|
| |
|
|
