arctanh(tan(tanh(x)))=x+2/3!*x^3+16/5!*x^5+496/7!*x^7+24064/9!*x^9...
A012171
arctanh(tan(tanh(x)))=x+2/3!*x^3+16/5!*x^5+496/7!*x^7+24064/9!*x^9...
Terms
- a(0) =1a(1) =2a(2) =16a(3) =496a(4) =24064a(5) =1908224a(6) =227958784a(7) =36620830720
External references
- oeis: A012171