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 | 33 |
| 5 | 135 |
| 6 | 633 |
| 7 | 3207 |
| 8 | 17589 |
| 9 | 102627 |
| 10 | 636033 |
| 11 | 4161141 |
| 12 | 28680717 |
| 13 | 207318273 |
| 14 | 1567344549 |
| 15 | 12345147705 |
| 16 | 101013795753 |
| 17 | 856212871761 |
| 18 | 7501911705747 |
| 19 | 67815650852235 |
| 20 | 631574151445665 |
| 21 | 6051983918989833 |
| 22 | 59605200185016639 |
| 23 | 602764245172225251 |
| 24 | 6252962956009863363 |