SudoKanard

  X-Sums Sudoku (from 2021 to 2022) Standard Sudoku rules apply. Each number outside the grid is the sum of the first X digits it sees in the corresponding row or column, where X is the first digit seen in that direction. Penpa link: https://git.io/Jya2N  

  Prime Sum Sudoku   Standard Sudoku rules apply. Additionally, every diamond symbol between two cells means that the corresponding digits add up to a prime number (3, 5, 7, 11, 13 or 17). Conversely, the lack of a diamond symbol between two orthogonally adjacent cells means that the corresponding digits do not add up to a prime number. Penpa link: https://git.io/JDvcN