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 | 2 |
| 2 | 16 |
| 3 | 224 |
| 4 | 4480 |
| 5 | 116480 |
| 6 | 3727360 |
| 7 | 141639680 |
| 8 | 6232145920 |
| 9 | 311607296000 |
| 10 | 17450008576000 |
| 11 | 1081900531712000 |
| 12 | 73569236156416000 |
| 13 | 5444123475574784000 |
| 14 | 435529878045982720000 |
| 15 | 37455569511954513920000 |
| 16 | 3445912395099815280640000 |
| 17 | 337699414719781897502720000 |