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) |
|---|---|
| 1 | 1 |
| 2 | 120 |
| 3 | 1 |
| 4 | 14400 |
| 5 | 840 |
| 6 | 1 |
| 7 | 1728000 |
| 8 | 619200 |
| 9 | 3360 |
| 10 | 1 |
| 11 | 207360000 |
| 12 | 447552000 |
| 13 | 9086400 |
| 14 | 10080 |
| 15 | 1 |
| 16 | 24883200000 |
| 17 | 322444800000 |
| 18 | 23345280000 |
| 19 | 76824000 |
| 20 | 25200 |
| 21 | 1 |
| 22 | 2985984000000 |
| 23 | 232185139200000 |
| 24 | 59152550400000 |
| 25 | 539602560000 |
| 26 | 457848000 |