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 | -7 |
| 2 | 23 |
| 3 | -35 |
| 4 | 973 |
| 5 | -245 |
| 6 | 7943 |
| 7 | -1295 |
| 8 | 31813 |
| 9 | -7721 |
| 10 | 288715 |
| 11 | -13475 |
| 12 | 128296423 |
| 13 | -882557 |
| 14 | -4891999 |
| 15 | 33870025 |
| 16 | 26217383381 |
| 17 | -2149340753 |
| 18 | -2830613025019 |
| 19 | 167302324405 |
| 20 | 101475278720663 |
| 21 | -16020469382309 |
| 22 | -4469247530896841 |
| 23 | 1848020660952865 |
| 24 | 11126033993150564743 |