Number of n-bead necklaces labeled with numbers -2..2 not allowing reversal, with sum zero and first differences in -2..2.

A208987

Number of n-bead necklaces labeled with numbers -2..2 not allowing reversal, with sum zero and first differences in -2..2.

Terms

    a(0) =1a(1) =2a(2) =3a(3) =7a(4) =17a(5) =51a(6) =155a(7) =508a(8) =1683a(9) =5709a(10) =19581a(11) =68047a(12) =238513a(13) =843280a(14) =3002105a(15) =10755341a(16) =38742697a(17) =140247035a(18) =509913321a(19) =1861307488a(20) =6818552671a(21) =25059962507a(22) =92376046425a(23) =341446354053

External references