E.g.f.: sech(exp(x)-cos(x)).

Terms

a(0) =1a(1) =0a(2) =-1a(3) =-6a(4) =-11a(5) =80a(6) =923a(7) =3682a(8) =-26567a(9) =-585120a(10) =-3969849a(11) =24427370a(12) =948294477a(13) =9793100720a(14) =-42570639997