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 | -3 |
| 3 | 14 |
| 4 | -11 |
| 5 | -81 |
| 6 | 282 |
| 7 | -57 |
| 8 | -2043 |
| 9 | 5405 |
| 10 | 2417 |
| 11 | -46476 |
| 12 | 94522 |
| 13 | 110512 |
| 14 | -943407 |
| 15 | 1505289 |
| 16 | 2807589 |
| 17 | -16888311 |
| 18 | 23645199 |
| 19 | 46006542 |
| 20 | -265972791 |
| 21 | 472882620 |
| 22 | 187884672 |
| 23 | -3981273597 |
| 24 | 14234579226 |
| 25 | -19187383356 |
| 26 | -78662039004 |
| 27 | 502118911904 |
| 28 | -847583768679 |
| 29 | -2627514175002 |