tanh(arctan(arctanh(x)))=x-2/3!*x^3+24/5!*x^5-496/7!*x^7+24192/9!*x^9...

A012236

tanh(arctan(arctanh(x)))=x-2/3!*x^3+24/5!*x^5-496/7!*x^7+24192/9!*x^9...

Terms

    a(0) =1a(1) =-2a(2) =24a(3) =-496a(4) =24192a(5) =-1246464a(6) =150408192a(7) =-12132673536

External references