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 | 0 |
| 2 | -1 |
| 3 | -1 |
| 4 | -1 |
| 5 | -1 |
| 6 | 1 |
| 7 | 8 |
| 8 | 23 |
| 9 | 45 |
| 10 | 55 |
| 11 | -14 |
| 12 | -317 |
| 13 | -1095 |
| 14 | -2459 |
| 15 | -3574 |
| 16 | -681 |
| 17 | 16124 |
| 18 | 64605 |
| 19 | 159483 |
| 20 | 260869 |
| 21 | 134374 |
| 22 | -906919 |
| 23 | -4228769 |
| 24 | -11317061 |
| 25 | -20327731 |
| 26 | -15742753 |
| 27 | 52640154 |
| 28 | 293447719 |
| 29 | 847451759 |
| 30 | 1648865921 |
| 31 | 1636313816 |
| 32 | -2986606297 |
| 33 | -21074495982 |