Expansion of e.g.f.: sech(log(x+1)-arcsin(x)).

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =-3a(5) =10a(6) =-100a(7) =525a(8) =-4935a(9) =32940a(10) =-339750a(11) =2618275a(12) =-30387775a(13) =251013750a(14) =-3301268100a(15) =26222434875a(16) =-400587471375