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 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | -3 |
| 5 | 2 |
| 6 | 1 |
| 7 | -8 |
| 8 | 144 |
| 9 | 6 |
| 10 | 1 |
| 11 | -15 |
| 12 | 2304 |
| 13 | -97200 |
| 14 | 24 |
| 15 | 1 |
| 16 | -24 |
| 17 | 14400 |
| 18 | -22579200 |
| 19 | 914457600 |
| 20 | 120 |
| 21 | 1 |
| 22 | -35 |
| 23 | 57600 |
| 24 | -857304000 |
| 25 | 7517247897600 |
| 26 | -119833267276800 |
| 27 | 720 |
| 28 | 1 |
| 29 | -48 |
| 30 | 176400 |
| 31 | -13548902400 |
| 32 | 3163657512960000 |
| 33 | -85018329720343756800 |
| 34 | 218719679433615360000 |
| 35 | 5040 |