8
1
3
9
9
5
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3
1
8
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6
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1
9
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9
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5
1
6
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3
8
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1
Nikoli, the Japanese puzzle company that popularized Sudoku, requires all their puzzles to be created by hand — no computers.
Nikoli, the Japanese puzzle company that popularized Sudoku, requires all their puzzles to be created by hand — no computers.
Euler's "problème des 36 officiers" — an unsolvable 6×6 Latin square — is a direct mathematical precursor to Sudoku.
Euler's "problème des 36 officiers" — an unsolvable 6×6 Latin square — is a direct mathematical precursor to Sudoku.