Number of subsets of the n-th roots of 1 with absolute value of sum = 1.

Terms

a(0) =0a(1) =1a(2) =2a(3) =6a(4) =8a(5) =10a(6) =36a(7) =14a(8) =64a(9) =72a(10) =180a(11) =22a(12) =720a(13) =26a(14) =924a(15) =600a(16) =2048a(17) =34a(18) =10800a(19) =38a(20) =12240a(21) =2856a(22) =22572a(23) =46a(24) =144000