189607197domain: NAppears in sequencesa(n) = 20*a(n-1) - a(n-2) with a(0) = 0, a(1) = 3.at n=7A001084Denominators of continued fraction convergents to sqrt(11).at n=13A041015Denominators of continued fraction convergents to sqrt(44).at n=27A041075Denominators of continued fraction convergents to sqrt(176).at n=13A041325