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

Terms

a(0) =1a(1) =0a(2) =0a(3) =6a(4) =24a(5) =0a(6) =360a(7) =5040a(8) =20160a(9) =60480a(10) =1814400a(11) =19958400a(12) =99792000a(13) =1037836800a(14) =21794572800a(15) =228843014400