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 | 1 |
| 3 | 19 |
| 4 | 57 |
| 5 | 121 |
| 6 | 783 |
| 7 | 2861 |
| 8 | 8133 |
| 9 | 37160 |
| 10 | 143419 |
| 11 | 468816 |
| 12 | 1876855 |
| 13 | 7263468 |
| 14 | 25496863 |
| 15 | 97187247 |
| 16 | 372086645 |
| 17 | 1352780401 |
| 18 | 5071962134 |
| 19 | 19220628318 |
| 20 | 71025008365 |
| 21 | 265095817718 |
| 22 | 997839772024 |
| 23 | 3713274525679 |
| 24 | 13851695644227 |
| 25 | 51940567251136 |
| 26 | 193830054345968 |