No more lucky numbers
The brief
Normal Sudoku rules apply. Orthogonally adjacent digits never sum to either 7 or 13, e.g. a 4 is never adjacent to either 3 or 9.
by sujoyku by sujoyku
Normal Sudoku rules apply. Orthogonally adjacent digits never sum to either 7 or 13, e.g. a 4 is never adjacent to either 3 or 9.