176421domain: NAppears in sequencesNumbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 40.at n=20A031718a(n) = 441*n^2 + 21.at n=20A15860321*n^4 - 36*n^3 + 25*n^2 - 8*n + 1.at n=10A239426