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 | 0 |
| 1 | 1 |
| 2 | 19 |
| 3 | 299 |
| 4 | 4578 |
| 5 | 71394 |
| 6 | 1153956 |
| 7 | 19471500 |
| 8 | 343976400 |
| 9 | 6366517200 |
| 10 | 123418922400 |
| 11 | 2503748556000 |
| 12 | 53091962697600 |
| 13 | 1175271048201600 |
| 14 | 27123099523027200 |
| 15 | 651708291206649600 |
| 16 | 16282170039031142400 |