1. DonationPawnokeyhole
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    22 Jun '05 09:45
    I tried and solved my first (easy) Sudoku puzzle recently. It set me to wondering however: What is fewest number of initial entries into a 9 x 9 sudoku grid that permit such a puzzle to be solved? I suspect the number can be formally arrived at, but I don't know how. Any takers?

    Aiden
  2. Subscribersonhouse
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    22 Jun '05 10:41
    On the sudoku site the puzzles there show either 3 or 4 numbers
    in each sub grid. So your only possiblity is 1 or 2 as smaller, not
    much of a range. 1 you could eliminate as allowing many solutions
    so the idea is to figure out if 2 in each grid could be set up
    to have only one solution, I think not. I think with 2 in each grid you
    have many more solutions so it looks to me like 3 and 4 are the
    minimum already.
  3. Standard memberPalynka
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    22 Jun '05 12:25
    17 is the answer.
  4. Subscribersonhouse
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    22 Jun '05 15:18
    Originally posted by Palynka
    17 is the answer.
    I had considered that, as well as 69 but the philosophical implications
    stymied me from venturing a valid logically unimpeachable arguement
    considered as a devils advocacy type of involvement with the
    fundamental numerical formulations.
  5. Standard memberThe Plumber
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    22 Jun '05 17:03
    Originally posted by Palynka
    17 is the answer.
    Huh uh...42. You should know that!
  6. Standard memberXanthosNZ
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    22 Jun '05 19:071 edit
    + 3 + + + + 9 + +
    6 + + 4 + + + + +
    + + + + + + 7 + +
    + 7 + 2 9 + + + +
    + + + 3 + + + 6 +
    + + + + + + + 4 +
    4 + + + + 5 + 8 +
    + + + + 7 + 3 + +
    + + 1 + + + + + +

    OK I doubt this will work. But there is a 17 number setup with a unique solution. No 16 numbers setups with unique solutions have been discovered but they haven't been shown not to exist.

    EDIT: Well it worked kind of.
  7. Standard memberThe Plumber
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    22 Jun '05 19:59
    Oh, you meant 17 was the answer to the Soduku thing, I was thinking of Life, the Universe, and Everything.

    nevermind....😀
  8. Standard memberPalynka
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    22 Jun '05 20:09
    Originally posted by The Plumber
    Oh, you meant 17 was the answer to the Soduku thing, I was thinking of Life, the Universe, and Everything.

    nevermind....😀
    The answer to that is, of course, the answer to the Soduku thing added to the number of months of the year and a lot of bad luck.

    That's how I got to the answer to the Soduku thing

    42 = 12 + 13 + X
    X = 17
  9. Subscribersonhouse
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    22 Jun '05 22:14
    Originally posted by XanthosNZ
    + 3 + + + + 9 + +
    6 + + 4 + + + + +
    + + + + + + 7 + +
    + 7 + 2 9 + + + +
    + + + 3 + + + 6 +
    + + + + + + + 4 +
    4 + + + + 5 + 8 +
    + + + + 7 + 3 + +
    + + 1 + + + + ...[text shortened]... have been discovered but they haven't been shown not to exist.

    EDIT: Well it worked kind of.
    well that blows my 3 and 4 thing. The puzzle I saw on the sudoku
    site had 6 3's and 3 4's (30) It just seemed to allow more
    solutions if you had less occupied squares.
    So the key is the *position* in the squares.
  10. Subscribersonhouse
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    22 Jun '05 22:34
    check out this site:
    http://www.shef.ac.uk/~pm1afj/sudoku/
  11. Subscribersonhouse
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    22 Jun '05 22:36
    also this one:
    http://en.wikipedia.org/wiki/Sudoku#Rules_and_terminology
  12. Standard memberorfeo
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    28 Jun '05 22:16
    Originally posted by sonhouse
    well that blows my 3 and 4 thing. The puzzle I saw on the sudoku
    site had 6 3's and 3 4's (30) It just seemed to allow more
    solutions if you had less occupied squares.
    So the key is the *position* in the squares.
    They've just started doing these in my local newspaper. The ones I've seen have 3 or 4 entries in SOME subsquares, but definitely not every subsquare.
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