Number of 7-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and first differences in -n..n.

A208998

Number of 7-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and first differences in -n..n.

Terms

    a(0) =9a(1) =155a(2) =1111a(3) =4935a(4) =16307a(5) =44209a(6) =104001a(7) =219929a(8) =428031a(9) =779487a(10) =1344353a(11) =2215747a(12) =3514415a(13) =5393753a(14) =8045199a(15) =11704103a(16) =16655941a(17) =23243017a(18) =31871521a(19) =43019059a(20) =57242537a(21) =75186543a(22) =97592047a(23) =125305621a(24) =159288983a(25) =200629037a(26) =250548251

External references