Number of n-bead necklaces labeled with numbers -3..3 allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
A209480
Number of n-bead necklaces labeled with numbers -3..3 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) =4a(2) =7a(3) =35a(4) =140a(5) =731a(6) =3740a(7) =20888a(8) =118137a(9) =687981a(10) =4059192a(11) =24292229a(12) =146840708a(13) =895753665a(14) =5505619880a(15) =34065921090
External references
- oeis: A209480