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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 5040 |
| 8 | 40320 |
| 9 | 181440 |
| 10 | 604800 |
| 11 | 1663200 |
| 12 | 3991680 |
| 13 | 8648640 |
| 14 | 17297280 |
| 15 | 32432400 |
| 16 | 57657600 |
| 17 | 98017920 |
| 18 | 160392960 |
| 19 | 253955520 |
| 20 | 390700800 |
| 21 | 586051200 |
| 22 | 859541760 |
| 23 | 1235591280 |
| 24 | 1744364160 |
| 25 | 2422728000 |
| 26 | 3315312000 |
| 27 | 4475671200 |
| 28 | 5967561600 |
| 29 | 7866331200 |