Exponential Riordan array [sech(2x), arctan(tanh(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