Unit line segments of the square lattice joined end to end — also called polyedges or polyforms of the square grid's edges.
The 5 free tristicks.
| Figure | Order | Free | One-sided | Fixed | Verified |
|---|---|---|---|---|---|
| monostick | 1 | 1 | 1 | 2 | ✓ 15/15 |
| distick | 2 | 2 | 2 | 6 | ✓ 15/15 |
| tristick | 3 | 5 | 7 | 22 | ✓ 15/15 |
| tetrastick | 4 | 16 | 25 | 88 | ✓ 15/15 |
| pentastick | 5 | 55 | 99 | 372 | ✓ 15/15 |
| hexastick | 6 | 222 | 416 | 1,628 | ✓ 15/15 |
| heptastick | 7 | 950 | 1,854 | 7,312 | ✓ 15/15 |
Reference sequences: Free A019988, One-Sided A151537, Fixed A096267.