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 | 7 |
| 2 | 100 |
| 3 | 945 |
| 4 | 5392 |
| 5 | 23401 |
| 6 | 93312 |
| 7 | 397585 |
| 8 | 1941760 |
| 9 | 10609137 |
| 10 | 61466176 |
| 11 | 364568617 |
| 12 | 2179768320 |
| 13 | 13065520825 |
| 14 | 78371693632 |
| 15 | 470196375201 |
| 16 | 2821126684672 |
| 17 | 16926683582305 |
| 18 | 101559990680640 |
| 19 | 609359787056377 |