arcsinh(arctan(arctan(x)))=x-5/3!*x^3+137/5!*x^5-9141/7!*x^7...

A012207

arcsinh(arctan(arctan(x)))=x-5/3!*x^3+137/5!*x^5-9141/7!*x^7...

Terms

    a(0) =1a(1) =-5a(2) =137a(3) =-9141a(4) =1130993a(5) =-225155941a(6) =66037540345

External references