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 | 3 |
| 2 | 18 |
| 3 | 165 |
| 4 | 2016 |
| 5 | 30783 |
| 6 | 564048 |
| 7 | 12057825 |
| 8 | 294587136 |
| 9 | 8096756763 |
| 10 | 247266851328 |
| 11 | 8306410495485 |
| 12 | 304403359942656 |
| 13 | 12085026305182743 |
| 14 | 516690458532292608 |
| 15 | 23668814542820609145 |
| 16 | 1156515067746149400576 |
| 17 | 60041982382475841900723 |
| 18 | 3300519734382436473765888 |