Expansion of e.g.f.: tan(log(1+tanh(x))).

Terms

a(0) =0a(1) =1a(2) =-1a(3) =2a(4) =-10a(5) =46a(6) =-226a(7) =1532a(8) =-11880a(9) =96136a(10) =-882376a(11) =9179312a(12) =-102310000a(13) =1223945776a(14) =-15941391376a(15) =222827194592