Number of distinct nonzero absolute values of Sum_{j=1..n} sigma_j * exp(i * Pi * j / n) where sigma_j = +- 1.
A013914
Number of distinct nonzero absolute values of Sum_{j=1..n} sigma_j * exp(i * Pi * j / n) where sigma_j = +- 1.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =4a(6) =8a(7) =12a(8) =16a(9) =33a(10) =62a(11) =67a(12) =186a(13) =316a(14) =280a(15) =1040a(16) =1963a(17) =1702a(18) =6830a(19) =10751a(20) =8679a(21) =45838a(22) =88255a(23) =56292a(24) =264838a(25) =624778a(26) =348817a(27) =2208496a(28) =4526585
External references
- oeis: A013914