Number of n-bead necklaces labeled with numbers -2..2 not allowing reversal, with sum zero with no three beads in a row equal.
A208939
Number of n-bead necklaces labeled with numbers -2..2 not allowing reversal, with sum zero with no three beads in a row equal.
Terms
- a(0) =1a(1) =3a(2) =6a(3) =22a(4) =68a(5) =264a(6) =988a(7) =3954a(8) =15980a(9) =66146a(10) =277190a(11) =1177152a(12) =5047672a(13) =21838420a(14) =95184446a(15) =417606390a(16) =1842715198a(17) =8172736366a(18) =36412668752a(19) =162897497434a(20) =731442664136
External references
- oeis: A208939