16536848domain: NAppears in sequencesa(n) = 6*a(n-2) + a(n-4), where a(0) = 2, a(1) = 8, a(2) = 13, a(3) = 49.at n=17A228469a(n) = 6*a(n-2) + a(n-4), where a(0) = 5, a(1) = 8, a(2) = 30, a(3) = 49.at n=17A228472Numerators of continued fraction convergents to sqrt(10)/2 = sqrt(5/2) = A020797 + 1.at n=27A295333