A328488 - OEIS

%I #7 Oct 17 2019 18:48:55

%S 1,1,5,34,307,3456,46659,734882,13227995,267871036,6027206803,

%T 149176155030,4027831914099,117816299188472,3711283196035523,

%U 125258162280991858,4509378597919760779,172486973301491042964,6985853719202139488211,298650859698906574479278

%N Expansion of e.g.f. 1 / (2 - exp(x * exp(x))).

%F a(0) = 1; a(n) = Sum_{k=1..n} binomial(n,k) * A000248(k) * a(n-k).

%F a(n) ~ n! / (2*log(2) * (1 + LambertW(log(2))) * LambertW(log(2))^n). - _Vaclav Kotesovec_, Oct 17 2019

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

%Y Cf. A000248, A000670, A003725, A007550, A083355, A292952.

%K nonn

%O 0,3

%A _Ilya Gutkovskiy_, Oct 16 2019