sec(tan(arctanh(x)))=1+1/2!*x^2+21/4!*x^4+1101/6!*x^6+107209/8!*x^8...
A012183
sec(tan(arctanh(x)))=1+1/2!*x^2+21/4!*x^4+1101/6!*x^6+107209/8!*x^8...
Terms
- a(0) =1a(1) =1a(2) =21a(3) =1101a(4) =107209a(5) =16711481a(6) =3810146205
External references
- oeis: A012183