How can you arrange 77 dots so that there are 66 lines of 33 colinear dots?

1 Answer
Jun 24, 2016

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Explanation:

Here's one solution:

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Bonus

This is an example of a problem that is very difficult to solve in the general case. The maximum number lines of 33 dots in nn dots follows the sequence (catalogued as A003035 in the online encyclopedia of integer sequences) that starts:

0, 0, 1, 1, 2, 4, 6, 7, 10, 12, 16, 19, 22, 260,0,1,1,2,4,6,7,10,12,16,19,22,26

The next number in the sequence is known to be 3131 or 3232, but it is an unsolved problem which one it is.