E.g.f. exp( x^2 * exp(x) ).

Terms

a(0) =1a(1) =0a(2) =2a(3) =6a(4) =24a(5) =140a(6) =870a(7) =5922a(8) =45416a(9) =381096a(10) =3442410a(11) =33382910a(12) =345803172a(13) =3801763836a(14) =44156760830a(15) =539962736250