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 | 12 |
| 4 | -8 |
| 5 | 1 |
| 6 | 60 |
| 7 | -60 |
| 8 | 15 |
| 9 | -1 |
| 10 | 360 |
| 11 | -480 |
| 12 | 180 |
| 13 | -24 |
| 14 | 1 |
| 15 | 2520 |
| 16 | -4200 |
| 17 | 2100 |
| 18 | -420 |
| 19 | 35 |
| 20 | -1 |
| 21 | 20160 |
| 22 | -40320 |
| 23 | 25200 |
| 24 | -6720 |
| 25 | 840 |
| 26 | -48 |
| 27 | 1 |
| 28 | 181440 |
| 29 | -423360 |
| 30 | 317520 |
| 31 | -105840 |
| 32 | 17640 |
| 33 | -1512 |
| 34 | 63 |
| 35 | -1 |
| 36 | 1814400 |
| 37 | -4838400 |
| 38 | 4233600 |