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 | 0 |
| 3 | -3 |
| 4 | -5 |
| 5 | 12 |
| 6 | 71 |
| 7 | 7 |
| 8 | -1028 |
| 9 | -2573 |
| 10 | 14793 |
| 11 | 100188 |
| 12 | -128831 |
| 13 | -3445791 |
| 14 | -5741800 |
| 15 | 113954461 |
| 16 | 601512787 |
| 17 | -3296210612 |
| 18 | -41316895641 |
| 19 | 37322755431 |
| 20 | 2570678600548 |
| 21 | 6983413204755 |
| 22 | -149303353515823 |
| 23 | -1080122148248420 |
| 24 | 7405149869523649 |
| 25 | 119115584584019713 |