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 | -3 |
| 3 | 12 |
| 4 | -58 |
| 5 | 318 |
| 6 | -1896 |
| 7 | 11966 |
| 8 | -78595 |
| 9 | 531486 |
| 10 | -3674324 |
| 11 | 25845131 |
| 12 | -184348434 |
| 13 | 1330147092 |
| 14 | -9690872427 |
| 15 | 71189146313 |
| 16 | -526703176813 |
| 17 | 3921274277132 |
| 18 | -29354616797397 |
| 19 | 220824254874928 |
| 20 | -1668453804382315 |
| 21 | 12655766723174710 |
| 22 | -96340024533522759 |
| 23 | 735747052686408916 |
| 24 | -5635489764030599334 |