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3 in a row = bad (Posted on 2006-04-26) Difficulty: 4 of 5
For n=3,4,5,6,7,8 find:

a) The minimum number of counters that need be placed on a nxn chessboard such that no additional counters can be placed without creating any straight line of 3;

b) The maximum number of counters that can be placed on a nxn chessboard such that no three lie in a straight line.

Remember that positions like A1, B3, and C5 are in a straight line.
(Try to continue the sequences if you can)

See The Solution Submitted by Jer    
Rating: 4.5000 (2 votes)

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Some Thoughts Possible minimum? | Comment 3 of 13 |

For part a), doing a quick trial and error I've found:

 n  minimum
-----------
 3    4
 4    4
 5    8
 6    8
 7    12

I don't know if those are the actual minimums required, but it's the best I've been able to accomplish so far, and it seems to make a nice little pattern...


  Posted by tomarken on 2006-04-26 14:41:35
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