Expansion of tanh(tanh(log(1+x))).

Terms

a(0) =0a(1) =1a(2) =-1a(3) =-2a(4) =18a(5) =-44a(6) =-300a(7) =3928a(8) =-12544a(9) =-193160a(10) =3128040a(11) =-11235872a(12) =-311721168a(13) =5932512496a(14) =-21553521808