Free polypents may be reflected as well as rotated. One-sided polypents may be rotated but not reflected.
| Order | Free | One-Sided |
|---|---|---|
| 1 | 1 | 1 |
| 2 | 1 | 1 |
| 3 | 2 | 2 |
| 4 | 7 | 11 |
| 5 | 25 | 43 |
| 6 | 118 | 223 |
| 7 | 551 | 1 072 |
| 8 | 2 812 | 5 564 |
| 9 | 14 445 | 28 747 |
| 10 | 76 092 | 151 897 |
| 11 | 403 976 | 807 245 |
| 12 | 2 167 116 | 4 332 812 |
Matthias Koch and Sascha Kurz have since enumerated polypents up through order 16. You may see some of their results at Professor Kurz's Generalized Polyomino Enumeration Page.
The enumeration for free polypents is A103465 in the On-Line Encyclopedia of Integer Sequences.
