Expansion of e.g.f. exp(x)/cosh(2*x).

Terms

a(0) =1a(1) =1a(2) =-3a(3) =-11a(4) =57a(5) =361a(6) =-2763a(7) =-24611a(8) =250737a(9) =2873041a(10) =-36581523a(11) =-512343611a(12) =7828053417a(13) =129570724921