80768domain: NAppears in sequencesarctanh(arctan(arctanh(x)))=x+2/3!*x^3+32/5!*x^5+1168/7!*x^7+80768/9!*x^9...at n=4A012237Number of 5-tuples of different integers from [ 1,n ] with no common factors among triples.at n=31A015646E.g.f. satisfies: A(x) = 1/(1 - sin(x*A(x))).at n=6A201627