T(n,k) is the number of n-bead necklaces labeled with numbers -k..k allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
A209485
T(n,k) is the number of n-bead necklaces labeled with numbers -k..k 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) =1a(2) =2a(3) =1a(4) =3a(5) =1a(6) =1a(7) =4a(8) =4a(9) =4a(10) =1a(11) =5a(12) =7a(13) =15a(14) =4a(15) =1a(16) =6a(17) =12a(18) =35a(19) =38a(20) =11a(21) =1a(22) =7a(23) =17a(24) =72a(25) =140a(26) =136a(27) =15a(28) =1a(29) =8
External references
- oeis: A209485