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

Terms

a(0) =0a(1) =1a(2) =-2a(3) =5a(4) =-15a(5) =54a(6) =-240a(7) =1350a(8) =-9450a(9) =78120a(10) =-725760a(11) =7371000a(12) =-81081000a(13) =965487600a(14) =-12454041600a(15) =173675502000