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 | 41 |
| 2 | 1640 |
| 3 | 65600 |
| 4 | 2624000 |
| 5 | 104960000 |
| 6 | 4198400000 |
| 7 | 167935999180 |
| 8 | 6717439934400 |
| 9 | 268697596064820 |
| 10 | 10747903790145600 |
| 11 | 429916149507936000 |
| 12 | 17196645896401920000 |
| 13 | 687865832499456000000 |
| 14 | 27514633165713408671580 |