sec(sec(x)*arctan(x))=1+1/2!*x^2+9/4!*x^4+345/6!*x^6+14833/8!*x^8...
A012812
sec(sec(x)*arctan(x))=1+1/2!*x^2+9/4!*x^4+345/6!*x^6+14833/8!*x^8...
Terms
- a(0) =1a(1) =1a(2) =9a(3) =345a(4) =14833a(5) =1493265a(6) =158895033a(7) =30935964969
External references
- oeis: A012812