1296477domain: NAppears in sequencesNumber of n-bead necklaces with beads of 2 colors and primitive period n, when turning over is allowed.at n=26A001371Number of primitive (period n) bracelets using exactly two different colored beads.at n=25A056348Numbers m > 4 such that [m-2..m+2] belong to A327261.at n=27A345357