Normal Sudoku rules apply, i.e. every row, column and 3×3 box needs to contain all the digits from 1 to 9 exactly once each.
The two main diagonals must both contain all the numbers from 1 to 9 once each.
A cell that contains a digit x can't have a taxicab distance of exactly x from another cell with the digit x.
A taxicab distance from cell A to cell B is the minimum possible distance from cell A to cell B when traversed only through orthogonal cells. For example, any cells that are a chess knight's move away from each other have a taxicab distance of 3 from one another, since a chess knight goes 2 cells in one direction and 1 in a perpendicular direction.
The ruleset was inspired by Madmahogany's Manhattan Sudoku. The full Sudoku grid as well as a few others like this were found by Realshaggy algorithmically.
Solution code: Row 3, Column 7
on 15. June 2020, 21:01 by Madmahogany
Nice one!
on 15. June 2020, 19:19 by JGLP
Image of sudoku was missing