683289domain: NAppears in sequencesNumber of ways to color vertices of a heptagon using <= n colors, allowing only rotations.at n=9A054621Number of n-bead necklaces with 9 colors.at n=7A054628T(n,k) = Sum_{d|k} phi(d)*n^(k/d)/k, triangle read by rows, T(n,k) for n >= 1 and 1 <= k <= n.at n=42A054630