sec(cos(x)*arctan(x))=1+1/2!*x^2-15/4!*x^4+105/6!*x^6+8897/8!*x^8...

A012507

sec(cos(x)*arctan(x))=1+1/2!*x^2-15/4!*x^4+105/6!*x^6+8897/8!*x^8...

Terms

    a(0) =1a(1) =1a(2) =-15a(3) =105a(4) =8897a(5) =-664815a(6) =-4523343a(7) =8138992953a(8) =-972054629887

External references