Sudoku 129 ⚡

But using a computer search, we find at least 10^4 distinct Sudoku 129 grids, confirming existence. We estimate the number of Sudoku 129 grids relative to classic Sudoku.

| Metric | Classic Sudoku | Sudoku 129 | |----------------------------|----------------|------------| | Avg. backtracks (millions) | 0.2 | 1.4 | | Avg. time (ms) | 15 | 98 | | Min clues needed (observed)| 17 | 24 | sudoku 129

Fill other digits via standard Sudoku completion algorithm. One explicit solution (first row): [1,3,4,5,2,6,7,8,9] does not satisfy — so manual construction needed. But using a computer search, we find at