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

Terms

a(0) =0a(1) =1a(2) =-2a(3) =5a(4) =-19a(5) =104a(6) =-706a(7) =5662a(8) =-53082a(9) =570600a(10) =-6897016a(11) =92565296a(12) =-1366706848a(13) =22016867248a(14) =-384226243584