Number of n-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
A209477
Number of n-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
Terms
- a(0) =1a(1) =3a(2) =7a(3) =72a(4) =866a(5) =16660a(6) =401634a(7) =11891268a(8) =413867410a(9) =16583242015
External references
- oeis: A209477