Number of n-bead necklaces labeled with numbers -2..2 not allowing reversal, with sum zero and first and second differences in -2..2.
A209001
Number of n-bead necklaces labeled with numbers -2..2 not allowing reversal, with sum zero and first and second differences in -2..2.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =3a(4) =5a(5) =10a(6) =23a(7) =66a(8) =167a(9) =445a(10) =1171a(11) =3167a(12) =8569a(13) =23618a(14) =65589a(15) =183955a(16) =518183a(17) =1467671a(18) =4172881a(19) =11913595a(20) =34128769a(21) =98093579a(22) =282770735a(23) =817397180a(24) =2368770203
External references
- oeis: A209001