Expansion of e.g.f. exp(arctanh(tan(x))).

Terms

a(0) =1a(1) =1a(2) =1a(3) =5a(4) =17a(5) =121a(6) =721a(7) =6845a(8) =58337a(9) =698161a(10) =7734241a(11) =111973685a(12) =1526099057a(13) =25947503401a(14) =419784870961