Number of n-bead necklaces of 6 colors allowing reversal, with no adjacent beads having the same color.

A208542

Number of n-bead necklaces of 6 colors allowing reversal, with no adjacent beads having the same color.

Terms

    a(0) =6a(1) =15a(2) =20a(3) =120a(4) =312a(5) =1505a(6) =5580a(7) =25395a(8) =108520a(9) =493131a(10) =2219460a(11) =10196680a(12) =46950120a(13) =218102685a(14) =1017252828a(15) =4768969770a(16) =22439395680a(17) =105966797755a(18) =501933850740

External references