sec(arctan(x)+tan(x))=1+4/2!*x^2+80/4!*x^4+4384/6!*x^6+436992/8!*x^8...
A013007
sec(arctan(x)+tan(x))=1+4/2!*x^2+80/4!*x^4+4384/6!*x^6+436992/8!*x^8...
Terms
- a(0) =1a(1) =4a(2) =80a(3) =4384a(4) =436992a(5) =70425984a(6) =16592126976
External references
- oeis: A013007