No-three-in-line $D(1)$

The largest number of points of the $1 \times 1$ grid with no three on a line.

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.

• Lower bound: $1$ Checked construction
  no-three-in-line-1-lower-1, submitted by daniel-munro, 2026-11-05
• Upper bound: None yet

Updates from the literature

• Lower bound: $1$
  Trivial or easy according to the secondary source.
  [via Sequence A272651 in the OEIS]
• Upper bound: $1$
  Trivial or easy according to the secondary source.
  [via Sequence A272651 in the OEIS]