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 | 2 |
| 2 | 8 |
| 3 | 48 |
| 4 | 128 |
| 5 | 3840 |
| 6 | 46080 |
| 7 | 14336 |
| 8 | 10321920 |
| 9 | 185794560 |
| 10 | 6553600 |
| 11 | 81749606400 |
| 12 | 78479622144 |
| 13 | 209924915200 |
| 14 | 1428329123020800 |
| 15 | 42849873690624000 |
| 16 | 170993385472000 |
| 17 | 7611536747003904 |
| 18 | 1678343852714360832000 |
| 19 | 747740921331712000 |
| 20 | 2551082656125828464640000 |