Number of n-bead necklaces labeled with numbers -3..3 allowing reversal, with sum zero.

A208820

Number of n-bead necklaces labeled with numbers -3..3 allowing reversal, with sum zero.

Terms

    a(0) =1a(1) =4a(2) =8a(3) =38a(4) =155a(5) =828a(6) =4390a(7) =25202a(8) =146803a(9) =878708a(10) =5330524a(11) =32785934a(12) =203687695a(13) =1276913732a(14) =8065359582a(15) =51282069040

External references