cosh(sec(x)-sech(x)) = 1+12/4!*x^4+8512/8!*x^8+34406592/12!*x^12...

A013513

cosh(sec(x)-sech(x)) = 1+12/4!*x^4+8512/8!*x^8+34406592/12!*x^12...

Terms

    a(0) =1a(1) =12a(2) =8512a(3) =34406592a(4) =471749623552

External references