Sandwich Sudoku #56
In each cell of the NxN grid, enter a number in the range 1–N. Each number must appear exactly once in each row and column, and in each grey and white block (but not in each region with a given number).
Additional rules: A number located at the edge of the grid shows the sum of the numbers between the cell with the 1 and the cell with the 9.
Short manual
Combinations tables give all the valid combinations for a given sum and number of digits. You can also use the calculator.
Enter the sum and number of digits in the fields below, and click the Calculate button.