Sudokus that no one can solve, not only including Sodukus which is very difficult but also that no one trying to solve it.

1-November-2020

- Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions.
- Some intersections of the grid lines are marked by a number and an operator (+, -, x, /) in a circle. The number is the result of the operation, applied to both pairs of diagonally opposite cells. An E in the circle indicates that all four adjacent digits are even, while an O indicates that all four adjacent digits are odd.

1-November-2020

- Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions.
- Some intersections of the grid lines are marked by a number and an operator (+, -, x, /) in a circle. The number is the result of the operation, applied to both pairs of diagonally opposite cells. An E in the circle indicates that all four adjacent digits are even, while an O indicates that all four adjacent digits are odd.

5-November-2020

- Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions.
- Some intersections of the grid lines are marked by a number and an operator (+, -, x, /) in a circle. The number is the result of the operation, applied to both pairs of diagonally opposite cells. An E in the circle indicates that all four adjacent digits are even, while an O indicates that all four adjacent digits are odd.

5-November-2020

5-November-2020

5-November-2020

6-November-2020

6-November-2020

9-November-2020

- A number between two cells indicates the difference of the numbers in these cells. A number between four cells indicates the difference between two diagonally adjacent cells, either top left + right bottom (\) or top right + bottom left (/). If one of the characters < or > is specified the apex of the angle points to the smaller of these numbers.

9-November-2020

- A number between two cells indicates the difference of the numbers in these cells. A number between four cells indicates the difference between two diagonally adjacent cells, either top left + right bottom (\) or top right + bottom left (/). If one of the characters < or > is specified the apex of the angle points to the smaller of these numbers.

10-November-2020

- The digits in two orthogonally adjacent cells cannot have a sum of either 5 or 10.

10-November-2020

- The digits in two orthogonally adjacent cells cannot have a sum of either 5 or 10.

10-November-2020

- A number at the edge of the diagram indicates the difference between the first and the last number in the corresponding row or column.

10-November-2020

- A number at the edge of the diagram indicates the difference between the first and the last number in the corresponding row or column.

10-November-2020

- A number between two cells indicates the difference of the numbers in these cells. A number between four cells indicates the difference between two diagonally adjacent cells, either top left + right bottom (\) or top right + bottom left (/). If one of the characters < or > is specified the apex of the angle points to the smaller of these numbers.

10-November-2020

10-November-2020

- Digits along each line are monotonically increasing or decreasing.

10-November-2020

- Digits along each line are monotonically increasing or decreasing.

11-November-2020

- Digits along each marked line are either all odd or all even.

11-November-2020

- Digits along each marked line are either all odd or all even.

11-November-2020

- Digits along each marked line are either all odd or all even.

11-November-2020

- Digits along each marked line are either all odd or all even.

12-November-2020

- Digits along each line are monotonically increasing or decreasing.

12-November-2020

- Digits along each line are monotonically increasing or decreasing.

12-November-2020

- If digit ‘n’ is placed in a cell with an arrow, digit ‘n+1’ must be placed in one of the cells pointed by the arrow.

12-November-2020

- If digit ‘n’ is placed in a cell with an arrow, digit ‘n+1’ must be placed in one of the cells pointed by the arrow.

17-November-2020

17-November-2020

19-November-2020

- A dot between two cells indicates that the digits in the two cells form a double digit square number in the reading direction. there are no square numbers marked by a dot.

19-November-2020

- A dot between two cells indicates that the digits in the two cells form a double digit square number in the reading direction. there are no square numbers marked by a dot.

20-November-2020

- A number at the edge of the diagram indicates the difference between the first and the last number in the corresponding row or column.

20-November-2020

20-November-2020

20-November-2020

20-November-2020

- Digits along each line are monotonically increasing or decreasing.

20-November-2020

- Digits along each line are monotonically increasing or decreasing.

22-November-2020

22-November-2020