a(n) = n! * [x^n] exp(n*x)*tan(x).

Terms

a(0) =0a(1) =1a(2) =4a(3) =29a(4) =288a(5) =3641a(6) =55872a(7) =1008349a(8) =20923392a(9) =490730641a(10) =12836633600a(11) =370512824285