cos(arctanh(x)*arctan(x)) = 1-12/4!*x^4-9968/8!*x^8-77575872/12!*x^12...

A012732

cos(arctanh(x)*arctan(x)) = 1-12/4!*x^4-9968/8!*x^8-77575872/12!*x^12...

Terms

    a(0) =1a(1) =-12a(2) =-9968a(3) =-77575872

External references