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 | 9 |
| 3 | 135 |
| 4 | 2835 |
| 5 | 76545 |
| 6 | 2525985 |
| 7 | 98513415 |
| 8 | 4433103675 |
| 9 | 226088287425 |
| 10 | 12887032383225 |
| 11 | 811883040143175 |
| 12 | 56019929769879075 |
| 13 | 4201494732740930625 |
| 14 | 340321073352015380625 |
| 15 | 29607933381625338114375 |
| 16 | 2753537804491156444636875 |
| 17 | 272600242644624488019050625 |