arctanh(cos(x)*arctan(x))=x-3/3!*x^3-27/5!*x^5+777/7!*x^7+48905/9!*x^9...

A012505

arctanh(cos(x)*arctan(x))=x-3/3!*x^3-27/5!*x^5+777/7!*x^7+48905/9!*x^9...

Terms

    a(0) =1a(1) =-3a(2) =-27a(3) =777a(4) =48905a(5) =-4320107a(6) =-424303635a(7) =77237001761

External references