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 | 1 |
| 2 | -6 |
| 3 | 224 |
| 4 | -39424 |
| 5 | 30277632 |
| 6 | -98180268032 |
| 7 | 1321338098679808 |
| 8 | -73064711504598663168 |
| 9 | 16493270769791857518968832 |
| 10 | -15132641904367108441083979235328 |
| 11 | 56258298143912014448000446346897129472 |
| 12 | -845539117695226477286180063077230730209656832 |