Number of 7-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero and first and second differences in -n..n.

A208974

Number of 7-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero and first and second differences in -n..n.

Terms

    a(0) =2a(1) =15a(2) =87a(3) =371a(4) =1185a(5) =3186a(6) =7425a(7) =15658a(8) =30368a(9) =55222a(10) =95087a(11) =156612a(12) =248194a(13) =380753a(14) =567639a(15) =825586a(16) =1174510a(17) =1638724a(18) =2246594a(19) =3032025a(20) =4033918a(21) =5298001a(22) =6876080a(23) =8828154a(24) =11221516a(25) =14133153a(26) =17648642a(27) =21864897a(28) =26888831a(29) =32840460

External references