Number of subsets of the n-th roots of unity that sum to 1.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =1a(5) =6a(6) =1a(7) =8a(8) =4a(9) =18a(10) =1a(11) =60a(12) =1a(13) =66a(14) =20a(15) =128a(16) =1a(17) =600a(18) =1a(19) =612a(20) =68a(21) =1026a(22) =1a(23) =6000a(24) =16a(25) =4098a(26) =256a(27) =8580a(28) =1a(29) =95226