Number of n-bead necklaces labeled with numbers -7..7 allowing reversal, with sum zero and first differences in -7..7.
A209031
Number of n-bead necklaces labeled with numbers -7..7 allowing reversal, with sum zero and first differences in -7..7.
Terms
- a(0) =1a(1) =4a(2) =12a(3) =88a(4) =625a(5) =5648a(6) =52208a(7) =505857a(8) =4992048a(9) =50169067a(10) =510807173a(11) =5260218485a(12) =54684221779a(13) =573168585795
External references
- oeis: A209031