Expansion of e.g.f. exp( x * exp(-x) ).

Terms

a(0) =1a(1) =1a(2) =-1a(3) =-2a(4) =9a(5) =-4a(6) =-95a(7) =414a(8) =49a(9) =-10088a(10) =55521a(11) =-13870a(12) =-2024759a(13) =15787188a(14) =-28612415a(15) =-616876274a(16) =7476967905a(17) =-32522642896a(18) =-209513308607