This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 9 | 1 |
| 10 | 27 |
| 11 | 378 |
| 12 | 3681 |
| 13 | 28134 |
| 14 | 180198 |
| 15 | 1007370 |
| 16 | 5051790 |
| 17 | 23173047 |
| 18 | 98644395 |
| 19 | 394006761 |
| 20 | 1489460724 |
| 21 | 5365964511 |
| 22 | 18526724685 |
| 23 | 61587671283 |
| 24 | 197885754837 |
| 25 | 616568620176 |
| 26 | 1868127089697 |
| 27 | 5517376711191 |
| 28 | 15917134652829 |
| 29 | 44935916034951 |
| 30 | 124340811582540 |
| 31 | 337706753653476 |