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A109111
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(1/sqrt(595))((sqrt(595)+26)(125+5sqrt(595))^n+(sqrt(595)-26)(125-5sqrt(595))^n).
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0
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2, 510, 126000, 31117500, 7684875000, 1897880625000, 468706500000000, 115753214531250000, 28586773757812500000, 7059878528554687500000, 1743529551820312500000000, 430587479058662109375000000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| Kekule numbers for certain benzenoids.
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REFERENCES
| S. J. Cyvin and I. Gutman, Kekule structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (p.292).
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FORMULA
| G.f.=2(1+5z)/(1-250z+750z^2).
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MAPLE
| a:=n->(1/sqrt(595))*((sqrt(595)+26)*(125+5*sqrt(595))^n+(sqrt(595)-26)*(125-5*sqrt(595))^n): seq(expand(a(n)), n=0..13);
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CROSSREFS
| Sequence in context: A024032 A172232 A109032 * A004886 A139302 A003391
Adjacent sequences: A109108 A109109 A109110 * A109112 A109113 A109114
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KEYWORD
| nonn
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AUTHOR
| Emeric Deutsch (deutsch(AT)duke.poly.edu), Jun 19 2005
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