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 | -5 |
| 3 | -17 |
| 4 | 19 |
| 5 | 211 |
| 6 | 181 |
| 7 | -2015 |
| 8 | -5837 |
| 9 | 12259 |
| 10 | 91585 |
| 11 | 29965 |
| 12 | -1033955 |
| 13 | -2347955 |
| 14 | 7953115 |
| 15 | 43864543 |
| 16 | -11941037 |
| 17 | -559875245 |
| 18 | -942036911 |
| 19 | 5060812717 |
| 20 | 21502740649 |
| 21 | -20676139991 |
| 22 | -307241918945 |
| 23 | -344022187613 |