sech(sin(sin(x)))=1-1/2!*x^2+13/4!*x^4-373/6!*x^6+19545/8!*x^8...

A012013

sech(sin(sin(x)))=1-1/2!*x^2+13/4!*x^4-373/6!*x^6+19545/8!*x^8...

Terms

    a(0) =1a(1) =-1a(2) =13a(3) =-373a(4) =19545a(5) =-1638569a(6) =201324773a(7) =-34084249501

External references