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 | 0 |
| 3 | 0 |
| 4 | -1 |
| 5 | 0 |
| 6 | 0 |
| 7 | -4 |
| 8 | 3 |
| 9 | 0 |
| 10 | -30 |
| 11 | 48 |
| 12 | -52 |
| 13 | -120 |
| 14 | 368 |
| 15 | -612 |
| 16 | -254 |
| 17 | 2524 |
| 18 | -6216 |
| 19 | 4040 |
| 20 | 11805 |
| 21 | -49400 |
| 22 | 68268 |
| 23 | 14928 |
| 24 | -332511 |
| 25 | 734508 |
| 26 | -568038 |
| 27 | -1641320 |
| 28 | 6202774 |
| 29 | -9239676 |
| 30 | -2503162 |
| 31 | 42749908 |
| 32 | -99021392 |
| 33 | 72255812 |
| 34 | 215763902 |