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 | 1 |
| 2 | 12 |
| 3 | 240 |
| 4 | 6720 |
| 5 | 241920 |
| 6 | 10644480 |
| 7 | 553512960 |
| 8 | 33210777600 |
| 9 | 2258332876800 |
| 10 | 171633298636800 |
| 11 | 14417197085491200 |
| 12 | 1326382131865190400 |
| 13 | 132638213186519040000 |
| 14 | 14324927024144056320000 |
| 15 | 1661691534800710533120000 |
| 16 | 206049750315288106106880000 |