tanh(tan(arcsinh(x)))=x-1/3!*x^3+1/5!*x^5-57/7!*x^7+4513/9!*x^9...

A012165

tanh(tan(arcsinh(x)))=x-1/3!*x^3+1/5!*x^5-57/7!*x^7+4513/9!*x^9...

Terms

    a(0) =1a(1) =-1a(2) =1a(3) =-57a(4) =4513a(5) =-362737a(6) =43685409a(7) =-7472568937

External references