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 | 3 |
| 3 | 5 |
| 4 | 105 |
| 5 | 945 |
| 6 | 3465 |
| 7 | 135135 |
| 8 | 2027025 |
| 9 | 883575 |
| 10 | 654729075 |
| 11 | 13749310575 |
| 12 | 8108567775 |
| 13 | 718713961875 |
| 14 | 213458046676875 |
| 15 | 121378104973125 |
| 16 | 191898783962510625 |
| 17 | 372509404162520625 |
| 18 | 73881031825566590625 |
| 19 | 8200794532637891559375 |
| 20 | 319830986772877770815625 |