E.g.f. satisfies: A(x) = exp(2*x) * A(-x).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =16a(5) =56a(6) =426a(7) =2262a(8) =26944a(9) =191536a(10) =3126160a(11) =27728240a(12) =575175624a(13) =6103078632a(14) =153600146896