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) |
|---|---|
| 1 | 1 |
| 2 | -1 |
| 3 | 1 |
| 4 | -13 |
| 5 | 3 |
| 6 | -37 |
| 7 | 9 |
| 8 | -1861 |
| 9 | 7 |
| 10 | -1491 |
| 11 | 93 |
| 12 | -81001 |
| 13 | 315 |
| 14 | -69705 |
| 15 | 1083 |
| 16 | -63586357 |
| 17 | 3855 |
| 18 | -438821 |
| 19 | 13797 |
| 20 | -822684711 |
| 21 | 49689 |
| 22 | -186369117 |
| 23 | 182361 |
| 24 | -704368012465 |
| 25 | 10485 |
| 26 | -10165801275 |
| 27 | 619549 |
| 28 | -9738266477517 |
| 29 | 9256395 |
| 30 | -566066862375 |
| 31 | 34636833 |
| 32 | -140047960975823893 |