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 | 0 |
| 4 | -2 |
| 5 | 3 |
| 6 | 0 |
| 7 | 16 |
| 8 | -30 |
| 9 | 15 |
| 10 | 0 |
| 11 | -272 |
| 12 | 588 |
| 13 | -420 |
| 14 | 105 |
| 15 | 0 |
| 16 | 7936 |
| 17 | -18960 |
| 18 | 16380 |
| 19 | -6300 |
| 20 | 945 |
| 21 | 0 |
| 22 | -353792 |
| 23 | 911328 |
| 24 | -893640 |
| 25 | 429660 |
| 26 | -103950 |
| 27 | 10395 |
| 28 | 0 |
| 29 | 22368256 |
| 30 | -61152000 |
| 31 | 65825760 |
| 32 | -36636600 |
| 33 | 11351340 |
| 34 | -1891890 |
| 35 | 135135 |