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) |
|---|---|
| 1 | 3 |
| 2 | 63 |
| 3 | 1575 |
| 4 | 5760 |
| 5 | 24255 |
| 6 | 51975 |
| 7 | 80640 |
| 8 | 172800 |
| 9 | 322560 |
| 10 | 403200 |
| 11 | 1209600 |
| 12 | 2822400 |
| 13 | 4435200 |
| 14 | 8870400 |
| 15 | 15523200 |
| 16 | 17740800 |
| 17 | 53222400 |
| 18 | 125798400 |
| 19 | 146764800 |