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 | 3 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 36 |
| 5 | 72 |
| 6 | -72 |
| 7 | 0 |
| 8 | 711 |
| 9 | 1080 |
| 10 | 144 |
| 11 | -2556 |
| 12 | 12852 |
| 13 | 23004 |
| 14 | -504 |
| 15 | -21192 |
| 16 | 122877 |
| 17 | 525996 |
| 18 | 69366 |
| 19 | -531576 |
| 20 | 1970154 |
| 21 | 7833756 |
| 22 | 6613164 |
| 23 | -12953124 |
| 24 | 24243261 |
| 25 | 137623572 |
| 26 | 130318974 |
| 27 | -138059232 |
| 28 | 115953372 |
| 29 | 2338653528 |