sech(sin(tan(x)))=1-1/2!*x^2+1/4!*x^4+47/6!*x^6+897/8!*x^8...

A012018

sech(sin(tan(x)))=1-1/2!*x^2+1/4!*x^4+47/6!*x^6+897/8!*x^8...

Terms

    a(0) =1a(1) =-1a(2) =1a(3) =47a(4) =897a(5) =26911a(6) =2176769a(7) =269558351a(8) =38463601409

External references