318955domain: NAppears in sequencesa(1) = 1. If a(n) is composite, a(n+1) = 2*a(n)+1; otherwise, a(n+1) = 2*a(n).at n=18A125050Number of length 2+2 0..n arrays with the sum of the maximum minus the median of adjacent triples multiplied by some arrangement of +-1 equal to zero.at n=33A251936