Evenly Counting
- Quadruples
The brief
- Normal (irregular) 6x6 sudoku rules apply, i.e. each row, column and region has to contain the digits from 1 to 6 once each.
- Even Counting Quadruples: A digit in a circle must appear in one of the four surrounding cells. Moreover, the digit indicates the number of even digits in these cells. For example, a 2 in a circle implies that the digit 2 appears in the four surrounding cells and they contain exactly two even and two odd digits.