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A147630
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9-factorial numbers (5).
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1
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1, 6, 90, 2160, 71280, 2993760, 152681760, 9160905600, 632102486400, 49303993939200, 4289447472710400, 411786957380198400, 43237630524920832000, 4929089879840974848000, 606278055220439906304000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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FORMULA
| a(n+1)=Sum_{k, 0<=k<=n}A132393(n,k)*6^k*9^(n-k). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 09 2008]
a(n)=n!*sum(k=1..n-1, binomial(k,n-k-1)*3^k*(-1)^(n-k-1)*binomial(n+k-1,n-1)))/n, also a(n)=n!*A097188(n). [Vladimir Kruchinin kru(AT)ie.tusur.ru, Apr 01 2011]
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MATHEMATICA
| s=1; lst={s}; Do[s+=n*s; AppendTo[lst, s], {n, 5, 2*5!, 9}]; lst
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PROG
| (Maxima)
a(n):=n!*sum(binomial(k, n-k-1)*3^k*(-1)^(n-k-1)*binomial(n+k-1, n-1), k, 1, n-1))/n; [Vladimir Kruchinin kru(AT)ie.tusur.ru Apr 01 2011]
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CROSSREFS
| Cf. A147629, A049211, A051232, A045756, A035012, A035013, A035017, A035018, A035020, A035022, A035023, A053116
Sequence in context: A002896 A004996 A001499 * A177584 A177558 A177580
Adjacent sequences: A147627 A147628 A147629 * A147631 A147632 A147633
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KEYWORD
| nonn
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AUTHOR
| Vladimir Orlovsky (4vladimir(AT)gmail.com), Nov 08 2008
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