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A035020
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One sixth of 9-factorial numbers.
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13
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1, 15, 360, 11880, 498960, 25446960, 1526817600, 105350414400, 8217332323200, 714907912118400, 68631159563366400, 7206271754153472000, 821514979973495808000, 101046342536739984384000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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LINKS
| Index entries for sequences related to factorial numbers
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FORMULA
| 6*a(n) = (9*n-3)(!^9) := product(9*j-3, j=1..n) = 3^n*2*A034000(n), 2*A034000(n)=(3*n-1)(!^3) := product(3*j-1, j=1..n); E.g.f. (-1+(1-9*x)^(-2/3))/6.
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MATHEMATICA
| s=1; lst={s}; Do[s+=n*s; AppendTo[lst, s], {n, 14, 2*5!, 9}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Nov 08 2008]
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CROSSREFS
| Cf. A007559, A034171, A045756, A035012, A035013, A035017, A035018, A035020-A035023.
Sequence in context: A202809 A184132 A012486 * A087330 A035274 A145409
Adjacent sequences: A035017 A035018 A035019 * A035021 A035022 A035023
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KEYWORD
| easy,nonn
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AUTHOR
| Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)
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