arctan(arctan(x)*tan(x))=2/2!*x^2-80/6!*x^6-2688/8!*x^8+260608/10!*x^10...

A012447

arctan(arctan(x)*tan(x))=2/2!*x^2-80/6!*x^6-2688/8!*x^8+260608/10!*x^10...

Terms

    a(0) =0a(1) =2a(2) =0a(3) =-80a(4) =-2688a(5) =260608a(6) =2928640a(7) =-463763456a(8) =-517376835584

External references