-1214813487domain: ZAppears in sequencesE.g.f.: exp(arctan(arctan(x))) = 1+x+1/2!*x^2-3/3!*x^3-15/4!*x^4+49/5!*x^5...at n=12A012203cosh(arctan(arctan(x)))=1+1/2!*x^2-15/4!*x^4+609/6!*x^6-48031/8!*x^8...at n=6A012210