Number of 6-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
A209118
Number of 6-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
Terms
- a(0) =15a(1) =238a(2) =1373a(3) =5032a(4) =14037a(5) =32802a(6) =67681a(7) =127310a(8) =222965a(9) =368920a(10) =582789a(11) =885874a(12) =1303543a(13) =1865552a(14) =2606403a(15) =3565722a(16) =4788571a(17) =6325826a(18) =8234535a(19) =10578240a(20) =13427355a(21) =16859514a(22) =20959913a(23) =25821668a(24) =31546173a(25) =38243442a(26) =46032457a(27) =55041546
External references
- oeis: A209118