E.g.f.: 2*exp(x)/(exp(2*x)+1+2*x).

Terms

a(0) =1a(1) =-1a(2) =3a(3) =-15a(4) =93a(5) =-725a(6) =6815a(7) =-74627a(8) =933849a(9) =-13148361a(10) =205690779a(11) =-3539545559a(12) =66446203637