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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 29 |
| 5 | 99 |
| 6 | 357 |
| 7 | 1351 |
| 8 | 5343 |
| 9 | 21993 |
| 10 | 93923 |
| 11 | 414969 |
| 12 | 1892277 |
| 13 | 8887291 |
| 14 | 42912261 |
| 15 | 212676951 |
| 16 | 1080355463 |
| 17 | 5617772049 |
| 18 | 29868493827 |
| 19 | 162204146857 |
| 20 | 898874710797 |
| 21 | 5078665886931 |
| 22 | 29232738375653 |
| 23 | 171294038649639 |
| 24 | 1021117638212079 |
| 25 | 6188701520663929 |