// output of ./demo/comb/root-sums-demo.cc: // Description: //% Zero-sums of roots of unity. //% Cf. OEIS sequence A164896. arg 1: 12 == n [n-th roots of unity] default=12 1: ............ 1 2: .....1.....1 6 0 6 3: ....11....11 6 0 1 6 7 4: ...1...1...1 4 0 4 8 5: ...1.1...1.1 6 0 2 6 8 6: ...11..1..11 12 L 0 1 4 7 8 7: ...111...111 6 0 1 2 6 7 8 8: ..1..1..1..1 3 0 3 6 9 9: ..1.11..1.11 6 0 1 3 6 7 9 10: ..11..11..11 4 0 1 4 5 8 9 11: ..11.1..11.1 6 0 2 3 6 8 9 12: ..11.11..111 12 L 0 1 2 5 6 8 9 13: ..1111..1111 6 0 1 2 3 6 7 8 9 14: .1.1.1.1.1.1 2 0 2 4 6 8 10 15: .1.111.1.111 6 0 1 2 4 6 7 8 10 16: .11.11.11.11 3 0 1 3 4 6 7 9 10 17: .111.111.111 4 0 1 2 4 5 6 8 9 10 18: .11111.11111 6 0 1 2 3 4 6 7 8 9 10 19: 111111111111 1 0 1 2 3 4 5 6 7 8 9 10 11 ct=19 act=2 sj=100