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 | 12 |
| 2 | 208 |
| 3 | 5208 |
| 4 | 179688 |
| 5 | 8175744 |
| 6 | 472666752 |
| 7 | 33625704960 |
| 8 | 2858013642240 |
| 9 | 281566521446400 |
| 10 | 30978996781363200 |
| 11 | 3583376917637529600 |
| 12 | 374151199254884352000 |
| 13 | 9777217907401555968000 |
| 14 | -16608590925355066982400000 |
| 15 | -10323797933882945175552000000 |