E.g.f.: log(1-x)*LambertW(-x).

Terms

a(0) =0a(1) =0a(2) =2a(3) =9a(4) =56a(5) =480a(6) =5394a(7) =75775a(8) =1280376a(9) =25270056a(10) =569899770a(11) =14444562803a(12) =406204015524