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A356459
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a(n) = n! * Sum_{k=1..n} Sum_{d|k} d/(k/d)!.
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2
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1, 7, 40, 281, 2006, 17677, 159020, 1678721, 18555850, 230978981, 2979853592, 43323807265, 644160764846, 10543905398405, 178896116995276, 3284281839169217, 61879477543508690, 1264313089711322821, 26333205612282941600, 588074615109602665601
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OFFSET
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1,2
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LINKS
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FORMULA
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a(n) = n! * Sum_{k=1..n} A354863(k)/k!.
E.g.f.: (1/(1-x)) * Sum_{k>0} k * (exp(x^k) - 1).
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PROG
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(PARI) a(n) = n!*sum(k=1, n, sumdiv(k, d, d/(k/d)!));
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(sum(k=1, N, k*(exp(x^k)-1))/(1-x)))
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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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