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E.g.f.: -log(2 - 1 / (1 + LambertW(-x))).
1

%I #8 Feb 16 2020 05:29:20

%S 1,5,41,466,6769,119736,2497585,60037328,1634619969,49733223040,

%T 1672657257721,61636181886720,2470033974057649,106970912288285696,

%U 4979259164362745025,247940951411958163456,13152705012933836446465,740578125097986605678592,44115815578591964641401289

%N E.g.f.: -log(2 - 1 / (1 + LambertW(-x))).

%F E.g.f.: -log(1 - Sum_{k>=1} k^k * x^k / k!).

%F a(n) = n^n + (1/n) * Sum_{k=1..n-1} binomial(n,k) * (n-k)^(n-k) * k * a(k).

%F a(n) ~ (n-1)! * 2^n * exp(n/2). - _Vaclav Kotesovec_, Feb 16 2020

%t nmax = 19; CoefficientList[Series[-Log[2 - 1/(1 + LambertW[-x])], {x, 0, nmax}], x] Range[0, nmax]! // Rest

%t a[n_] := a[n] = n^n + (1/n) Sum[Binomial[n, k] (n - k)^(n - k) k a[k], {k, 1, n - 1}]; Table[a[n], {n, 1, 19}]

%Y Cf. A000312, A001865, A133297, A202477, A210661, A308863, A323673, A332237.

%K nonn

%O 1,2

%A _Ilya Gutkovskiy_, Feb 07 2020