Expansion of e.g.f. 1/(1 - sin(2*x) / 2).

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =-8a(5) =-104a(6) =-688a(7) =-3088a(8) =-128a(9) =209536a(10) =3145472a(11) =29795072a(12) =139389952a(13) =-1715047424a(14) =-60056147968