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 | 167936000000 |
| 8 | 6717440000000 |
| 9 | 268697600000000 |
| 10 | 10747904000000000 |
| 11 | 429916160000000000 |
| 12 | 17196646400000000000 |
| 13 | 687865855999999999180 |
| 14 | 27514634239999999934400 |