Enter the digits from 1 to n into the diagram, so that there is every digit in every row and every column exactly once.
If there is a black circle between two cells, one of the numbers in these two cells must be twice the value of the number in the other cell. If there is a white circle between two cells, one of the numbers in these two cells must be one more than the number in the other cell. If there is no circle between two digits, none of these two properties may hold. The circle between 1 and 2 may be either black or white.
- On a hexagon where every digit may only occur once in every row.
- As a Sudoku with 3x3-blocks.
This puzzletype has been invented by Vladimir Portugalov (Belarus). The name means "dots" in Belarusian language.