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 | 0 |
| 2 | -12 |
| 3 | -480 |
| 4 | -15792 |
| 5 | 387840 |
| 6 | 232592448 |
| 7 | 44951262720 |
| 8 | 4538494871808 |
| 9 | -1173690989322240 |
| 10 | -1020600368000166912 |
| 11 | -406075179314308669440 |
| 12 | -50036577406600515366912 |
| 13 | 87776293107173235762462720 |