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 | 15 |
| 3 | 191 |
| 4 | 2414 |
| 5 | 31594 |
| 6 | 434568 |
| 7 | 6314664 |
| 8 | 97053936 |
| 9 | 1576890000 |
| 10 | 27046454400 |
| 11 | 488849155200 |
| 12 | 9293295110400 |
| 13 | 185464792800000 |
| 14 | 3878247384345600 |
| 15 | 84822225638169600 |
| 16 | 1937048605944883200 |
| 17 | 46113230058645657600 |