arctan(sin(arctanh(x)))=x-1/3!*x^3+9/5!*x^5-225/7!*x^7+3345/9!*x^9...

A012054

arctan(sin(arctanh(x)))=x-1/3!*x^3+9/5!*x^5-225/7!*x^7+3345/9!*x^9...

Terms

    a(0) =1a(1) =-1a(2) =9a(3) =-225a(4) =3345a(5) =-893025a(6) =-36212775a(7) =-20892252225

External references