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 | 32 |
| 5 | 118 |
| 6 | 455 |
| 7 | 1803 |
| 8 | 7304 |
| 9 | 30104 |
| 10 | 125834 |
| 11 | 532154 |
| 12 | 2272728 |
| 13 | 9788310 |
| 14 | 42464315 |
| 15 | 185394551 |
| 16 | 813950824 |
| 17 | 3591328136 |
| 18 | 15916173734 |
| 19 | 70819784774 |
| 20 | 316254424144 |
| 21 | 1416906860412 |
| 22 | 6367136425862 |
| 23 | 28690381745294 |