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 | 1 |
| 6 | 0 |
| 7 | 12 |
| 8 | -6 |
| 9 | 1 |
| 10 | 0 |
| 11 | -132 |
| 12 | 66 |
| 13 | -12 |
| 14 | 1 |
| 15 | 0 |
| 16 | 2280 |
| 17 | -1140 |
| 18 | 210 |
| 19 | -20 |
| 20 | 1 |
| 21 | 0 |
| 22 | -56760 |
| 23 | 28380 |
| 24 | -5240 |
| 25 | 510 |
| 26 | -30 |
| 27 | 1 |
| 28 | 0 |
| 29 | 1923600 |
| 30 | -961800 |
| 31 | 177660 |
| 32 | -17360 |
| 33 | 1050 |
| 34 | -42 |
| 35 | 1 |
| 36 | 0 |
| 37 | -85149960 |
| 38 | 42574980 |
| 39 | -7864920 |
| 40 | 769090 |
| 41 | -46760 |
| 42 | 1932 |
| 43 | -56 |
| 44 | 1 |