No-three-in-line $D(65)$
The largest number of points of the $65 \times 65$ grid with no three on a line.
Value: $130$ Verified lower bound
Verified bounds
Verified bounds come with a certificate that is checked automatically: a formal proof in Lean, or an explicit construction checked by a program. Submit a certificate.
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Lower bound:
$130$
Checked construction
no-three-in-line-65-lower-130, submitted by daniel-munro, 2026-11-05
[construction from M. Heule, personal communication, recorded on the no-three-in-line records page (2026-06-18).] - Upper bound: None yet
Updates from the literature
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Upper bound: $130$
Trivial or easy according to the secondary source.
[via No-three-in-line problem - Wikipedia] -
2026-06-18
Lower bound: $130$
M. Heule, personal communication, recorded on the no-three-in-line records page (2026-06-18).
[via The No-Three-in-Line Problem, Achim Flammenkamp, 2026-10-28]