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 | 6 |
| 2 | 48 |
| 3 | 264 |
| 4 | 1824 |
| 5 | 9672 |
| 6 | 67584 |
| 7 | 335928 |
| 8 | 2367552 |
| 9 | 13031040 |
| 10 | 94708224 |
| 11 | 454285152 |
| 12 | 3523559424 |
| 13 | 15677418768 |
| 14 | 113738502240 |
| 15 | 599516366592 |
| 16 | 4210539708672 |
| 17 | 20465720064000 |
| 18 | 154928015278080 |
| 19 | 735060126170880 |
| 20 | 5906693566844928 |
| 21 | 26937015875831424 |
| 22 | 188358079273592832 |