Expansion of e.g.f. exp(3 * x * cos(x)).

Terms

a(0) =1a(1) =3a(2) =9a(3) =18a(4) =-27a(5) =-552a(6) =-3051a(7) =-3504a(8) =102825a(9) =1043712a(10) =3192129a(11) =-41548416a(12) =-653192883a(13) =-3033406464a(14) =31367500173a(15) =670266381312