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

A209011

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

Terms

    a(0) =3a(1) =23a(2) =157a(3) =703a(4) =2313a(5) =6261a(6) =14701a(7) =31069a(8) =60429a(9) =109991a(10) =189627a(11) =312461a(12) =495497a(13) =760323a(14) =1133925a(15) =1649437a(16) =2347063a(17) =3275011a(18) =4490479a(19) =6060743a(20) =8064195a(21) =10591639a(22) =13747397a(23) =17650689a(24) =22436937a(25) =28259205a(26) =35289631a(27) =43720971a(28) =53768203a(29) =65670121

External references