Expansion of e.g.f. log(cosh(x) + tan(x)).

Terms

a(0) =0a(1) =1a(2) =0a(3) =1a(4) =-4a(5) =25a(6) =-120a(7) =761a(8) =-5024a(9) =42065a(10) =-378240a(11) =3898321a(12) =-42905344a(13) =521329705a(14) =-6794511360a(15) =96017526281