Number of subsets (up to cyclic shifts) of the n-th roots of 1 with zero sum.

Terms

a(0) =1a(1) =2a(2) =2a(3) =3a(4) =2a(5) =5a(6) =2a(7) =6a(8) =4a(9) =9a(10) =2a(11) =19a(12) =2a(13) =21a(14) =10a(15) =36a(16) =2a(17) =94a(18) =2a(19) =117a(20) =22a(21) =189a(22) =2a(23) =618a(24) =8a(25) =633a(26) =60a(27) =1203a(28) =2a(29) =6069