E.g.f.: exp(1/2! * x^2 * exp(-x)).

Terms

a(0) =1a(1) =0a(2) =1a(3) =-3a(4) =9a(5) =-40a(6) =210a(7) =-1176a(8) =7273a(9) =-49932a(10) =372060a(11) =-2971540a(12) =25359411a(13) =-230364498a(14) =2215550428a(15) =-22460391240a(16) =239236043985