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 | 4 |
| 3 | 42 |
| 4 | 704 |
| 5 | 16300 |
| 6 | 482112 |
| 7 | 17366776 |
| 8 | 737738752 |
| 9 | 36109329552 |
| 10 | 2001104000000 |
| 11 | 123856655495584 |
| 12 | 8468525621182464 |
| 13 | 633915692700252352 |
| 14 | 51562270240172425216 |
| 15 | 4528439794201950000000 |
| 16 | 427082984690083973562368 |
| 17 | 43049504748861000404766976 |