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 | 1 |
| 2 | 10 |
| 3 | 270 |
| 4 | 14040 |
| 5 | 1193400 |
| 6 | 150368400 |
| 7 | 26314470000 |
| 8 | 6104957040000 |
| 9 | 1813172240880000 |
| 10 | 670873729125600000 |
| 11 | 302564051835645600000 |
| 12 | 163384587991248624000000 |
| 13 | 104075982550425373488000000 |
| 14 | 77224379052415627128096000000 |
| 15 | 66026844089815361194522080000000 |
| 16 | 64442199831659792525853550080000000 |