Exponential Riordan array [sec(2x), arctanh(tan(x))].

Terms

a(0) =1a(1) =0a(2) =1a(3) =4a(4) =0a(5) =1a(6) =0a(7) =16a(8) =0a(9) =1a(10) =80a(11) =0a(12) =40a(13) =0a(14) =1a(15) =0a(16) =640a(17) =0a(18) =80a(19) =0a(20) =1a(21) =3904a(22) =0a(23) =2800a(24) =0a(25) =140a(26) =0a(27) =1a(28) =0a(29) =49152