sec(sec(x)*tanh(x))=1+1/2!*x^2+9/4!*x^4+297/6!*x^6+14385/8!*x^8...
A012838
sec(sec(x)*tanh(x))=1+1/2!*x^2+9/4!*x^4+297/6!*x^6+14385/8!*x^8...
Terms
- a(0) =1a(1) =1a(2) =9a(3) =297a(4) =14385a(5) =1207729a(6) =143876601a(7) =23841581337
External references
- oeis: A012838