Expansion of e.g.f. exp(x)*(tan(x)+sec(x))^2.

Terms

a(0) =1a(1) =3a(2) =9a(3) =29a(4) =105a(5) =433a(6) =2029a(7) =10709a(8) =63025a(9) =409713a(10) =2917749a(11) =22599389a(12) =189200745a(13) =1702839193a(14) =16397919469a(15) =168248900069