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 | -36 |
| 2 | 630 |
| 3 | -7148 |
| 4 | 59193 |
| 5 | -382032 |
| 6 | 2004938 |
| 7 | -8819856 |
| 8 | 33292656 |
| 9 | -109911296 |
| 10 | 322501266 |
| 11 | -852715008 |
| 12 | 2055752147 |
| 13 | -4563680868 |
| 14 | 9404597538 |
| 15 | -18107068172 |
| 16 | 32737836213 |
| 17 | -55804850136 |
| 18 | 89956581256 |
| 19 | -137430862056 |
| 20 | 199259540514 |
| 21 | -274319614896 |
| 22 | 358419693312 |
| 23 | -443688451632 |
| 24 | 518556849207 |
| 25 | -568577821788 |