1749780

Appears in sequences

• Number of reversible strings with n beads using exactly four different colors.at n=10A056311
• Number of primitive (aperiodic) reversible strings with n beads using exactly four different colors.at n=10A056320
• Triangle read by rows: T(n,k) is the number of rows of n colors with exactly k different colors counting chiral pairs as equivalent, i.e., the rows are reversible.at n=58A305621