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A356439
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Expansion of e.g.f. ( Product_{k>0} 1/(1 - k * x^k)^(1/k) )^(1/(1-x)).
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3
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1, 1, 6, 39, 344, 3410, 42234, 567126, 8812880, 149409144, 2793232440, 56224856160, 1234342760232, 28773852409848, 718719835537872, 19045601930731320, 534564416062012800, 15792205306586537280, 491639547448322794944, 16024048206145815040704
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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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a(0) = 1; a(n) = Sum_{k=1..n} A356436(k) * binomial(n-1,k-1) * a(n-k).
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PROG
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(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(1/prod(k=1, N, (1-k*x^k)^(1/k))^(1/(1-x))))
(PARI) a356436(n) = n!*sum(k=1, n, sumdiv(k, d, d^(k/d))/k);
a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=1, i, a356436(j)*binomial(i-1, j-1)*v[i-j+1])); v;
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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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