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 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 10 |
| 4 | 22 |
| 5 | -48 |
| 6 | 1332 |
| 7 | -4993 |
| 8 | 19214 |
| 9 | -49581 |
| 10 | 254382 |
| 11 | -1722923 |
| 12 | 10638103 |
| 13 | -66142706 |
| 14 | 328928511 |
| 15 | -1456443507 |
| 16 | 5695672798 |
| 17 | -31601720558 |
| 18 | 161632124933 |
| 19 | -847410385847 |
| 20 | 4341075327051 |
| 21 | -23587315770992 |
| 22 | 121139251802434 |
| 23 | -562846024950460 |