Consecutive Sudoku is a variant with the extra rule that orthogonally adjoining numbers are consecutive if and provided that there’s a dot between them. A Nonconsecutive Sudoku is one with no dots; no orthogonally adjoining numbers are consecutive. I have been making an attempt to make one just lately and my regular methodology of checking with a solver to see whether or not I’ve made the puzzle not possible is not working, because the “options” it spits out all fail the consecutiveness take a look at.
This makes me marvel what share of Sudoku options are additionally legitimate for Nonconsecutive Sudoku. I do know that there are 6.67 × 1021 legitimate Sudoku boards, ignoring symmetries/transformations. What number of of these are nonconsecutive, once more ignoring symmetries? (Laptop assist is clearly allowed for computation)