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A351433
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a(n) = n! * [x^n] 1/(1 + f^n(x)), where f(x) = exp(x) - 1.
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4
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1, -1, 0, 0, -2, -75, -3334, -192864, -14443260, -1372372623, -162009663365, -23314158802286, -4022712394579207, -820399656345934444, -195326656416326556562, -53709209673236813446542, -16896296201917398543629108, -6030879950631118091070849321
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OFFSET
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0,5
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LINKS
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FORMULA
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a(n) = T(n,n), T(n,k) = Sum_{j=0..n} Stirling2(n,j) * T(j,k-1), k>1, T(n,0) = (-1)^n * n!.
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MAPLE
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g:= x-> exp(x)-1:
a:= n-> n! * coeff(series(1/(1+(g@@n)(x)), x, n+1), x, n):
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MATHEMATICA
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T[n_, 0] := (-1)^n * n!; T[n_, k_] := T[n, k] = Sum[StirlingS2[n, j]*T[j, k - 1], {j, 0, n}]; a[n_] := T[n, n]; Array[a, 17, 0] (* Amiram Eldar, Feb 11 2022 *)
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PROG
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(PARI) T(n, k) = if(k==0, (-1)^n*n!, sum(j=0, n, stirling(n, j, 2)*T(j, k-1)));
a(n) = T(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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