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 | 9 |
| 2 | 252 |
| 3 | 10944 |
| 4 | 617472 |
| 5 | 41457024 |
| 6 | 3141499392 |
| 7 | 259346018304 |
| 8 | 22749987520512 |
| 9 | 2082519895670784 |
| 10 | 196336888097144832 |
| 11 | 18885576885968830464 |
| 12 | 1841197721072909156352 |
| 13 | 181107406524439376953344 |
| 14 | 17918621160090649673859072 |
| 15 | 1779590652288735614991335424 |