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 | 16 |
| 4 | 113 |
| 5 | 961 |
| 6 | 9430 |
| 7 | 104028 |
| 8 | 1267833 |
| 9 | 16866694 |
| 10 | 242836861 |
| 11 | 3758663745 |
| 12 | 62200007243 |
| 13 | 1095222618881 |
| 14 | 20433071584276 |
| 15 | 402407118276836 |
| 16 | 8338150233939377 |
| 17 | 181250019817152061 |
| 18 | 4122472220802095509 |