E.g.f. tanh(arctan(x)*log(x+1)).

Terms

a(0) =2a(1) =-3a(2) =0a(3) =-10a(4) =-32a(5) =1596a(6) =-10080a(7) =27936a(8) =-260928a(9) =1924560a(10) =33929280a(11) =-686630880a(12) =4846421760a(13) =-42426084960a(14) =778331473920