Expansion of exp(x)/cos(tanh(x)).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =4a(5) =-4a(6) =-32a(7) =-104a(8) =400a(9) =5392a(10) =3680a(11) =-167936a(12) =-719168a(13) =1592384a(14) =45313024a(15) =401669248a(16) =-1201882880a(17) =-50456008448a(18) =-190738937344