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 | 18 |
| 2 | 114 |
| 3 | 582 |
| 4 | 3466 |
| 5 | 20938 |
| 6 | 129642 |
| 7 | 813586 |
| 8 | 5161418 |
| 9 | 33012690 |
| 10 | 212531034 |
| 11 | 1375465890 |
| 12 | 8940439306 |
| 13 | 58322410658 |
| 14 | 381620168176 |
| 15 | 2503490173972 |
| 16 | 16459423126778 |
| 17 | 108417784128158 |
| 18 | 715300322712000 |
| 19 | 4725856346389840 |