3114015839domain: NAppears in sequencesa(n) = 9*a(n - 1) - a(n - 2) for n>1, a(0)=0, a(1)=1.at n=11A018913Denominators of continued fraction convergents to sqrt(77).at n=21A041137Denominators of continued fraction convergents to sqrt(308).at n=21A041581