-9841domain: ZAppears in sequencesa(n) = (-1)^n * (3^n - 1)/2.at n=9A076040a(n) = 4*a(n-1) - 7*a(n-2) + 6*a(n-3) - 3*a(n-4), starting with 0, 1, 2, 3.at n=19A134581