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 | 2 |
| 3 | 4 |
| 4 | 13 |
| 5 | 57 |
| 6 | 304 |
| 7 | 1937 |
| 8 | 14315 |
| 9 | 120264 |
| 10 | 1131896 |
| 11 | 11794453 |
| 12 | 134774963 |
| 13 | 1675630582 |
| 14 | 22516745452 |
| 15 | 325188337067 |
| 16 | 5022796990606 |
| 17 | 82620491929333 |
| 18 | 1441894214312037 |
| 19 | 26609607869036180 |
| 20 | 517741915593936360 |
| 21 | 10592513721179374467 |
| 22 | 227325651424365263577 |
| 23 | 5106351205789851629476 |