60111domain: NAppears in sequencesa(n) = 52*n^2 - 1.at n=33A158640For 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=11A345688a(n) = Sum_{d|n} (n/d)^(d-1) * binomial(d+n-2,n-1).at n=9A363666