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A355786
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E.g.f. satisfies A(x) = 1/(1 - 2*x)^(A(x)/2).
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2
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1, 1, 5, 42, 497, 7620, 143979, 3241406, 84847489, 2534788296, 85170416115, 3180919433802, 130771002469953, 5869920100483452, 285705285804636411, 14989889385040915830, 843420165009747027969, 50664760467069168337680, 3236433107379299238343779
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OFFSET
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0,3
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LINKS
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FORMULA
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E.g.f.: exp( -LambertW(log(1-2*x)/2) ).
a(n) = Sum_{k=0..n} 2^(n-k) * (k+1)^(k-1) * |Stirling1(n,k)|.
E.g.f.: 2*LambertW(log(1-2*x)/2) / log(1-2*x).
a(n) ~ 2^(n - 1/2) * n^(n-1) * exp(3/2 - n + 2*n*exp(-1)) / (exp(2*exp(-1)) - 1)^(n - 1/2). (End)
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PROG
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(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(-lambertw(log(1-2*x)/2))))
(PARI) a(n) = sum(k=0, n, 2^(n-k)*(k+1)^(k-1)*abs(stirling(n, k, 1)));
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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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