101080863domain: NAppears in sequencesNumerators of continued fraction convergents to sqrt(409).at n=13A041776The x member of the positive proper fundamental solution (x = x1(n), y = y1(n)) of the first class for the Pell equation x^2 - D(n)*y^2 = +8 for odd D(n) = A263012(n).at n=17A264349