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A109121
a(n) = 10(n+1)^3*(2n+1)(7n+5)^2.
0
250, 34560, 487350, 3028480, 12251250, 38016000, 98499310, 223948800, 461143530, 878560000, 1572243750, 2672386560, 4350609250, 6827950080, 10383558750, 15364096000, 22193838810, 31385491200, 43551700630
OFFSET
0,1
COMMENTS
Kekulé numbers for certain benzenoids.
REFERENCES
S. J. Cyvin and I. Gutman, Kekulé structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (p. 311).
FORMULA
G.f.: 10(25 + 3281z + 25068z^2 + 33404z^3 + 8539z^4 + 243z^5)/(1-z)^7.
MAPLE
a:=n->10*(n+1)^3*(2*n+1)*(7*n+5)^2: seq(a(n), n=0..28);
MATHEMATICA
Table[10(n+1)^3(2n+1)(7n+5)^2, {n, 0, 30}] (* Harvey P. Dale, Aug 07 2019 *)
CROSSREFS
Sequence in context: A249199 A249214 A249321 * A253005 A267972 A267995
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Jun 19 2005
STATUS
approved