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A108676 (n+1)^2*(n+2)(5n^2+15n+12)/24. +0
1
1, 16, 93, 340, 950, 2226, 4606, 8688, 15255, 25300, 40051, 60996, 89908, 128870, 180300, 246976, 332061, 439128, 572185, 735700, 934626, 1174426, 1461098, 1801200, 2201875, 2670876, 3216591, 3848068, 4575040, 5407950, 6357976 (list; graph; listen)
OFFSET

0,2

COMMENT

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.231, # 37).

FORMULA

G.f.=(1+10z+12z^2+2z^3)/(1-z)^6

MAPLE

a:=n->(n+1)^2*(n+2)*(5*n^2+15*n+12)/24: seq(a(n), n=0..36);

CROSSREFS

Sequence in context: A047674 A153029 A027938 this_sequence A159245 A066487 A128702

Adjacent sequences: A108673 A108674 A108675 this_sequence A108677 A108678 A108679

KEYWORD

nonn

AUTHOR

Emeric Deutsch (deutsch(AT)duke.poly.edu), Jun 17 2005

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Last modified December 2 11:54 EST 2009. Contains 167921 sequences.


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