517074domain: NAppears in sequencesNumber of magic labelings with magic sum n of 2nd graph shown in link.at n=23A244870For 1<=x<=n, 1<=y<=n, write gcd(x,y) = u*x+v*y with u,v minimal; a(n) = n^4*s, where s is the population variance of the values of v.at n=16A345688