280300164domain: NAppears in sequencesTrajectory of 397 under the map A340008: n -> n/2 if n is even, n-> n^2 - 1 if n is an odd prime, otherwise n -> n - 1.at n=20A340419a(0) = 397; a(n+1) = a(n)^2 if a(n) is prime, floor(a(n)/2) otherwise.at n=17A376801