Expansion of e.g.f. exp(x^2+3*x^3).

Terms

a(0) =1a(1) =0a(2) =2a(3) =18a(4) =12a(5) =360a(6) =3360a(7) =7560a(8) =183120a(9) =1814400a(10) =8195040a(11) =184615200a(12) =1976546880a(13) =14166472320a(14) =310589959680