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 | 6 |
| 3 | 46 |
| 4 | 376 |
| 5 | 2841 |
| 6 | 19718 |
| 7 | 128535 |
| 8 | 805848 |
| 9 | 4942711 |
| 10 | 29970542 |
| 11 | 180700389 |
| 12 | 1086570460 |
| 13 | 6525662885 |
| 14 | 39170135870 |
| 15 | 235062159691 |
| 16 | 1410477973872 |
| 17 | 8463133736523 |
| 18 | 50779476069198 |
| 19 | 304678570340665 |
| 20 | 1828075815690100 |
| 21 | 10968466276145161 |
| 22 | 65810827526263678 |