105638domain: NAppears in sequencesNumbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 50.at n=12A031728a(n) = Sum_{k + l*m <= n} (k + l*m), with 0 <= k,l,m <= n.at n=36A106846a(n) = 169*n^2 + 13.at n=25A158548