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 | 3 |
| 2 | 15 |
| 3 | 120 |
| 4 | 1080 |
| 5 | 14040 |
| 6 | 196560 |
| 7 | 3931200 |
| 8 | 82555200 |
| 9 | 1981324800 |
| 10 | 49533120000 |
| 11 | 1585059840000 |
| 12 | 52306974720000 |
| 13 | 1778437140480000 |
| 14 | 65802174197760000 |
| 15 | 2500482619514880000 |
| 16 | 112521717878169600000 |
| 17 | 5401042458152140800000 |