A012782 exp(sec(x)*arcsin(x))=1+x+1/2!*x^2+5/3!*x^3+17/4!*x^4+85/5!*x^5...
1, 1, 1, 5, 17, 85, 505, 3201, 25153, 204905, 1945265, 19581949, 217998673, 2608398013, 33522871785, 463598293497, 6789373095937, 106484041306577, 1755926841763681, 30821112722260469, 566210591513987345
Offset: 0