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 | 1 |
| 5 | -14 |
| 6 | 64 |
| 7 | -97 |
| 8 | -1376 |
| 9 | 15915 |
| 10 | -68820 |
| 11 | -467868 |
| 12 | 11504693 |
| 13 | -85105325 |
| 14 | -490922106 |
| 15 | 21504158897 |
| 16 | -242026388646 |
| 17 | -848338391966 |
| 18 | 80509815160192 |
| 19 | -1351044945506956 |
| 20 | 1506218518200935 |
| 21 | 472249651021870475 |
| 22 | -11783220545826576339 |
| 23 | 78093421491085905492 |