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# Sudokus that no one can solve

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

## Differences Sudoku

24-September-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.
• 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.  ## Differences Sudoku

24-September-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.
• 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. ## Cupid Sudoku

12-October-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.
• An arrow in a cell indicates that the number in this cell is repeated at least once in the direction the arrow points to.  ## Cupid Sudoku

12-October-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.
• An arrow in a cell indicates that the number in this cell is repeated at least once in the direction the arrow points to. ## Rossini Sudoku

14-October-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.
• The arrows outside the grid indicate that the nearest three digits in the corresponding direction are in ascending or descending order (the highest number is always in the direction of the arrow). All possible arrows are given, so if there is no arrow, the first three digits do not form an increasing sequence in either direction.  ## Rossini Sudoku

14-October-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.
• The arrows outside the grid indicate that the nearest three digits in the corresponding direction are in ascending or descending order (the highest number is always in the direction of the arrow). All possible arrows are given, so if there is no arrow, the first three digits do not form an increasing sequence in either direction. ## Non-Consecutive Sudoku

19-October-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.
• Digits in adjacent cells cannot be consecutive.  ## Non-Consecutive Sudoku

19-October-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.
• Digits in adjacent cells cannot be consecutive. ## Give me Five Sudoku

19-October-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.
• Sum and difference of two orthogonally adjacent numbers must not be 5.  ## Give me Five Sudoku

19-October-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.
• Sum and difference of two orthogonally adjacent numbers must not be 5. ## Creasing Sudoku

19-October-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.
• Digits along each line are monotonically increasing or decreasing.  ## Creasing Sudoku

19-October-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.
• Digits along each line are monotonically increasing or decreasing. ## Perfect Squares

20-October-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.
• 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.  ## Perfect Squares

20-October-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.
• 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. ## Mathrax Sudoku

20-October-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.  ## Mathrax Sudoku

20-October-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. ## Perfect Squares

21-October-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.
• 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.  ## Perfect Squares

21-October-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.
• 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. ## Mathrax Sudoku

21-October-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.  ## Mathrax Sudoku

21-October-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. ## Differences Sudoku

22-October-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.
• 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.  ## Differences Sudoku

22-October-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.
• 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. ## Creasing Sudoku

22-October-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.
• Digits along each line are monotonically increasing or decreasing.  ## Creasing Sudoku

22-October-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.
• Digits along each line are monotonically increasing or decreasing. ## Eliminate Sudoku

22-October-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.
• The number in a cell with an arrow must not be repeated in a cell the arrow points to.  ## Eliminate Sudoku

22-October-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.
• The number in a cell with an arrow must not be repeated in a cell the arrow points to. ## Perfect Squares

24-October-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.
• 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.  ## Perfect Squares

24-October-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.
• 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. ## Mathrax Sudoku

27-October-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.  ## Mathrax Sudoku

27-October-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. ## Perfect Squares

29-October-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.
• 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.  ## Perfect Squares

29-October-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.
• 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. ## Mathrax Sudoku

29-October-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.  ## Mathrax Sudoku

29-October-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. ## Arrow Sudoku

29-October-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.
• The sum of the digits along the path of each arrow equals the digit in the circled cell. Digits may repeat within an arrow shape.  ## Arrow Sudoku

29-October-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.
• The sum of the digits along the path of each arrow equals the digit in the circled cell. Digits may repeat within an arrow shape. ## Parity Lines Sudoku

29-October-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.
• Digits along each marked line are either all odd or all even.  ## Parity Lines Sudoku

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