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A292358
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E.g.f.: Product_{k>=1} 1/(1 + x^k/k).
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5
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1, -1, 1, -5, 20, -104, 584, -4304, 35720, -329160, 3239112, -36135912, 438454752, -5743527360, 80351263680, -1218698312064, 19599583392384, -334335747652224, 6019295318075520, -114911886106373760, 2305234779285164544, -48596575400453366784
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OFFSET
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0,4
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LINKS
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FORMULA
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E.g.f.: exp(Sum_{k>=1} Sum_{j>=1} (-1)^k*x^(j*k)/(k*j^k)). - Ilya Gutkovskiy, May 27 2018
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MATHEMATICA
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nmax = 20; CoefficientList[Series[Product[1/(1 + x^k/k), {k, 1, nmax}], {x, 0, nmax}], x] * Range[0, nmax]! (* Vaclav Kotesovec, Sep 15 2017 *)
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PROG
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(PARI) {a(n) = n!*polcoeff(1/prod(k=1, n, 1+x^k/k+x*O(x^n)), n)}
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CROSSREFS
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KEYWORD
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sign
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AUTHOR
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STATUS
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approved
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