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 | 2 |
| 2 | 8 |
| 3 | 24 |
| 4 | 216 |
| 5 | 4320 |
| 6 | 19008 |
| 7 | 103488 |
| 8 | 1292544 |
| 9 | 1548288 |
| 10 | 3264307200 |
| 11 | 24710676480 |
| 12 | 54623600640 |
| 13 | 16562257920 |
| 14 | 3345695539200 |
| 15 | 8216950210560 |
| 16 | 33673108783104000 |
| 17 | 205682009702400000 |
| 18 | 15655109317676236800 |
| 19 | 12302792042521559040000 |