Expansion of e.g.f. exp(1 - (1+x)^3).

Terms

a(0) =1a(1) =-3a(2) =3a(3) =21a(4) =-63a(5) =-423a(6) =1899a(7) =15201a(8) =-72063a(9) =-832491a(10) =3105459a(11) =60090093a(12) =-110508543a(13) =-5224722831a(14) =-3828328677a(15) =510699368313