223436800domain: NAppears in sequencesexp(arctanh(x) + arctan(x)) = 1 + 2*x + 4/2!*x^2 + 8/3!*x^3 + 16/4!*x^4 + 80/5!*x^5 +...at n=12A013174cos(arctanh(x)+arctan(x))=1-4/2!*x^2+16/4!*x^4-640/6!*x^6+21760/8!*x^8...at n=6A013179