Number of distinct values taken by the sums of all subsets of the n-th roots of unity.

Terms

a(0) =2a(1) =3a(2) =7a(3) =9a(4) =31a(5) =19a(6) =127a(7) =81a(8) =343a(9) =211a(10) =2047a(11) =361a(12) =8191a(13) =2059a(14) =14221a(15) =6561a(16) =131071a(17) =6859a(18) =524287a(19) =44521a(20) =778765a(21) =175099a(22) =8388607a(23) =130321a(24) =28629151a(25) =1586131a(26) =40353607a(27) =4239481a(28) =536870911a(29) =1360291