Whether $t(n)/n$ converges is unknown; the only quantitative prediction for its conjectural limit is the Guy–Kelly first-moment heuristic, giving $\pi/\sqrt3\ap
The Guy–Kelly first-moment heuristic places $m$ points uniformly on the $n\times n$ grid. Kudriashov's audit showed that at $m=2n$, $n=20$, it overestimates the
How does the grid differ from random line systems sharing its per-direction statistics? For $2n$-point no-three-in-line sets, $s(n)=R_2(n)P(\mathrm{void})$ unde
For $n\le74$ and $n=76$ the no-three-in-line optimum is known: $t(n)=2n$. Above that range the best values come from local search, and they fall from about $1.8