The New Sudoku Players' Forum

[Serg]

Hi, ton!

I think minimum numbers are about "floor(n^2 / 4) - (h - 1)(w - 1)".

Are "h" and "w" from your formula height and width of the box? (For 20 x 20 Sudoku h=4, w=5, n=20.) How did you get this formula? It gives 16 - minimal number of clues for 9 x 9 Sudoku. Almost right answer.

Serg

[ton]

Are "h" and "w" from your formula height and width of the box? (For 20 x 20 Sudoku h=4, w=5, n=20.)

Yes.

How did you get this formula?

Intuition.
I and my acquaintances call the formula "例の式"("rei no shiki").

It gives 16 - minimal number of clues for 9 x 9 Sudoku. Almost right answer.

I think that the formula give a value close to the minimum for other sizes too.