

A272651


The no3inline problem: maximal number of points from an n X n square grid so that no three lie on a line.


6



1, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92
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OFFSET

1,2


COMMENTS

a(47) is the first open case.
It is conjectured that a(n) < 2n for all sufficiently large n.
A000769 has an extensive list of references and links.
Comment from Warren D. Smith, May 10 2015: 2n is a trivial upper bound, because if you pick 2n+1 points, then some three must lie on a horizontal line.


LINKS



CROSSREFS



KEYWORD

nonn,more


AUTHOR



STATUS

approved



