Expansion of e.g.f. exp(x^4 * exp(-x)).

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =24a(5) =-120a(6) =360a(7) =-840a(8) =21840a(9) =-365904a(10) =3633840a(11) =-26619120a(12) =239512680a(13) =-3943797000a(14) =69258333144a(15) =-997361197560