Expansion of e.g.f. arctan(exp(x) - sec(x)).

Terms

a(0) =0a(1) =1a(2) =0a(3) =-1a(4) =-4a(5) =5a(6) =60a(7) =-61a(8) =-2504a(9) =-8695a(10) =100920a(11) =873479a(12) =-6889804a(13) =-142058995a(14) =-4843020a(15) =19728547019a(16) =98903242096