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A108676 (n+1)^2*(n+2)(5n^2+15n+12)/24. 0
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; 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.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: A153029 A027938 A185458 * A160750 A159245 A066487

Adjacent sequences:  A108673 A108674 A108675 * A108677 A108678 A108679

KEYWORD

nonn

AUTHOR

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

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Last modified February 16 01:31 EST 2012. Contains 205860 sequences.