Expansion of e.g.f. sec(x*exp(x)).

Terms

a(0) =1a(1) =0a(2) =1a(3) =6a(4) =29a(5) =180a(6) =1501a(7) =14434a(8) =154265a(9) =1856232a(10) =24953401a(11) =368767102a(12) =5936244533a(13) =103519338780