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 | 12 |
| 3 | -801 |
| 4 | -27248 |
| 5 | -389730 |
| 6 | -3120012 |
| 7 | -14532448 |
| 8 | -35492160 |
| 9 | -19420479 |
| 10 | 117458280 |
| 11 | 405309252 |
| 12 | 1029595248 |
| 13 | 887517566 |
| 14 | -3584009856 |
| 15 | -3351877470 |
| 16 | -1982054144 |
| 17 | -34455379518 |
| 18 | 33499242252 |
| 19 | 58483431740 |
| 20 | -28952389920 |
| 21 | 113929105248 |
| 22 | 227377787184 |
| 23 | -603011632584 |
| 24 | 182257162560 |