sec(sin(arctanh(x)))=1+1/2!*x^2+9/4!*x^4+201/6!*x^6+7921/8!*x^8...
A012061
sec(sin(arctanh(x)))=1+1/2!*x^2+9/4!*x^4+201/6!*x^6+7921/8!*x^8...
Terms
- a(0) =1a(1) =1a(2) =9a(3) =201a(4) =7921a(5) =447281a(6) =28121145a(7) =230243001a(8) =-940995291295
External references
- oeis: A012061