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 | 2 |
| 4 | 3 |
| 5 | -8 |
| 6 | -61 |
| 7 | -134 |
| 8 | 567 |
| 9 | 6908 |
| 10 | 29631 |
| 11 | -33857 |
| 12 | -1624011 |
| 13 | -13579197 |
| 14 | -42493684 |
| 15 | 449043601 |
| 16 | 8591509012 |
| 17 | 71167884338 |
| 18 | 153434398957 |
| 19 | -5188374785607 |
| 20 | -95914651874891 |
| 21 | -882652244738780 |
| 22 | -1819090127593647 |
| 23 | 96780404956817315 |
| 24 | 2051640887011218601 |