arctan(arctan(tanh(x)))=x-6/3!*x^3+184/5!*x^5-13584/7!*x^7...

A012224

arctan(arctan(tanh(x)))=x-6/3!*x^3+184/5!*x^5-13584/7!*x^7...

Terms

    a(0) =1a(1) =-6a(2) =184a(3) =-13584a(4) =1840768a(5) =-397140224a(6) =124961670144

External references