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 | 3 |
| 2 | -1 |
| 3 | 18 |
| 4 | -12 |
| 5 | 1 |
| 6 | 126 |
| 7 | -126 |
| 8 | 21 |
| 9 | -1 |
| 10 | 945 |
| 11 | -1260 |
| 12 | 315 |
| 13 | -30 |
| 14 | 1 |
| 15 | 7371 |
| 16 | -12285 |
| 17 | 4095 |
| 18 | -585 |
| 19 | 39 |
| 20 | -1 |
| 21 | 58968 |
| 22 | -117936 |
| 23 | 49140 |
| 24 | -9360 |
| 25 | 936 |
| 26 | -48 |
| 27 | 1 |
| 28 | 480168 |
| 29 | -1120392 |
| 30 | 560196 |
| 31 | -133380 |
| 32 | 17784 |
| 33 | -1368 |
| 34 | 57 |
| 35 | -1 |
| 36 | 3961386 |
| 37 | -10563696 |
| 38 | 6162156 |
| 39 | -1760616 |
| 40 | 293436 |
| 41 | -30096 |
| 42 | 1881 |
| 43 | -66 |
| 44 | 1 |
| 45 | 33011550 |
| 46 | -99034650 |
| 47 | 66023100 |