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A276506
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E.g.f.: exp(9*(exp(x)-1)).
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3
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1, 9, 90, 981, 11511, 144108, 1911771, 26730981, 392209380, 6016681467, 96202473183, 1599000785730, 27563715220509, 491777630207037, 9064781481234546, 172346601006842337, 3375007346801025099, 67983454804021156548, 1406921223577401454239, 29881379179971835132761
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OFFSET
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0,2
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COMMENTS
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Number of ways of placing n labeled balls into n unlabeled (but 9-colored) boxes.
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LINKS
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FORMULA
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G.f.: A(x) satisfies 9*(x/(1-x))*A(x/(1-x)) = A(x)-1; nine times the binomial transform equals this sequence shifted one place left.
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MAPLE
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a:= proc(n) option remember; `if`(n=0, 1,
(1+add(binomial(n-1, k-1)*a(n-k), k=1..n-1))*9)
end:
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MATHEMATICA
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Table[BellB[n, 9], {n, 0, 30}]
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PROG
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(PARI) my(x='x+O('x^99)); Vec(serlaplace(exp(9*(exp(x)-1)))) \\ Altug Alkan, Sep 17 2016
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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