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

Terms

a(0) =1a(1) =-2a(2) =-4a(3) =14a(4) =144a(5) =286a(6) =-5080a(7) =-61058a(8) =-186144a(9) =4016958a(10) =73395928a(11) =468915102a(12) =-4728823088a(13) =-167453193314a(15) =-406640603074