sech(sec(x)*tan(x))=1-1/2!*x^2-15/4!*x^4-177/6!*x^6+8225/8!*x^8...

A012800

sech(sec(x)*tan(x))=1-1/2!*x^2-15/4!*x^4-177/6!*x^6+8225/8!*x^8...

Terms

    a(0) =1a(1) =-1a(2) =-15a(3) =-177a(4) =8225a(5) =1259231a(6) =82092945a(7) =-6743602257

External references