A012801 exp(sec(x)*arctan(x))=1+x+1/2!*x^2+2/3!*x^3+5/4!*x^4+40/5!*x^5...
1, 1, 1, 2, 5, 40, 205, 576, 2473, 46208, 475385, 1293184, -2814227, 309637120, 5900398725, 5786437632, -532397600303, 7315622592512, 273302104270705, -347058934743040, -68724093821987755, 483735262691819520
Offset: 0