76884domain: NAppears in sequencesa(n) = A066158(n)-2 with a(0)=1.at n=10A192074Numbers such that k is the altitude of a Heronian triangle with sides m-13, m, m+13.at n=19A293846a(n) = Sum_{k=1..n} gcd(k, n)^3.at n=39A343497a(n) = Sum_{1 <= i, j, k <= n} gcd(i,j,k).at n=38A344522