876539domain: NAppears in sequencesa(1) = 1. If a(n) is prime, a(n+1) = 2*a(n); otherwise, a(n+1) = 2*a(n) + 1.at n=19A125049Number of length n+3 0..2 arrays with every four consecutive terms having the maximum of some two terms equal to the minimum of the remaining two terms.at n=17A249701