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

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =24a(5) =0a(6) =0a(7) =2520a(8) =20160a(9) =0a(10) =1209600a(11) =19958400a(12) =79833600a(13) =1556755200a(14) =39956716800a(15) =326918592000