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E.g.f.: Product_{k>=1} (1 - (exp(x) - 1)^k)^(1/k).
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%I #18 Jun 26 2021 08:58:13

%S 1,-1,-2,-3,-3,40,477,4375,45154,486817,5002397,54970652,732601449,

%T 10046371231,113632306694,1051655108629,12585372336141,

%U 202763995934160,-863641466773595,-247388278229558697,-10810815349601723990,-311011007642247422759

%N E.g.f.: Product_{k>=1} (1 - (exp(x) - 1)^k)^(1/k).

%C Stirling transform of A028343.

%H N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/StirlingTransform.html">Stirling Transform</a>

%F E.g.f.: exp( -Sum_{k>=1} d(k) * (exp(x) - 1)^k / k ), where d(n) is the number of divisors of n.

%F a(n) = Sum_{k=0..n} Stirling2(n,k) * A028343(k).

%t max = 21; Range[0, max]! * CoefficientList[Series[Product[(1 - (Exp[x] - 1)^k)^(1/k), {k, 1, max}], {x, 0, max}], x] (* _Amiram Eldar_, Jun 26 2021 *)

%o (PARI) my(N=40, x='x+O('x^N)); Vec(serlaplace(prod(k=1, N, (1-(exp(x)-1)^k)^(1/k))))

%o (PARI) my(N=40, x='x+O('x^N)); Vec(serlaplace(exp(-sum(k=1, N, numdiv(k)*(exp(x)-1)^k/k))))

%Y Cf. A000005, A028343, A048993, A336100, A345750, A345751, A345752.

%K sign

%O 0,3

%A _Seiichi Manyama_, Jun 26 2021