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

Terms

a(0) =1a(1) =0a(2) =0a(3) =1a(4) =5a(5) =16a(6) =52a(7) =274a(8) =1990a(9) =14354a(10) =99704a(11) =730225a(12) =6061013a(13) =56151330a(14) =551040830a(15) =5597109717a(16) =59324775741a(17) =664973687438