sech(sec(x)*arcsinh(x))=1-1/2!*x^2-3/4!*x^4-45/6!*x^6+2457/8!*x^8...

A012833

sech(sec(x)*arcsinh(x))=1-1/2!*x^2-3/4!*x^4-45/6!*x^6+2457/8!*x^8...

Terms

    a(0) =1a(1) =-1a(2) =-3a(3) =-45a(4) =2457a(5) =-36825a(6) =12566037a(7) =-1732392389a(8) =313988548273

External references