arctanh(arctan(arctan(x)))=x-2/3!*x^3+32/5!*x^5-1392/7!*x^7+118400/9!*x^9...
A012209
arctanh(arctan(arctan(x)))=x-2/3!*x^3+32/5!*x^5-1392/7!*x^7+118400/9!*x^9...
Terms
- a(0) =1a(1) =-2a(2) =32a(3) =-1392a(4) =118400a(5) =-16678144a(6) =3517084672
External references
- oeis: A012209