E.g.f.: Product_{k>=1} (1 - (exp(x) - 1)^k / k!).

Terms

a(0) =1a(1) =-1a(2) =-2a(3) =-2a(4) =7a(5) =78a(6) =513a(7) =2665a(8) =9406a(9) =-13902a(10) =-789143a(11) =-11806456a(12) =-140040408a(13) =-1463842226a(14) =-13377115923a(15) =-95264642343a(16) =-198034245627