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 | 5 |
| 2 | 38 |
| 3 | 430 |
| 4 | 6640 |
| 5 | 130200 |
| 6 | 3088560 |
| 7 | 85828080 |
| 8 | 2731899456 |
| 9 | 97956720000 |
| 10 | 3906077932800 |
| 11 | 171436911264000 |
| 12 | 8211994618982400 |
| 13 | 426284974571904000 |
| 14 | 23836815193556736000 |
| 15 | 1428394963614554880000 |
| 16 | 91316330157374106624000 |