sech(arctan(arcsin(x)))=1-1/2!*x^2+9/4!*x^4-249/6!*x^6+11953/8!*x^8...

A012202

sech(arctan(arcsin(x)))=1-1/2!*x^2+9/4!*x^4-249/6!*x^6+11953/8!*x^8...

Terms

    a(0) =1a(1) =-1a(2) =9a(3) =-249a(4) =11953a(5) =-992401a(6) =115133433a(7) =-19289685193

External references