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 | 0 |
| 2 | 6 |
| 3 | 8 |
| 4 | 54 |
| 5 | 144 |
| 6 | 636 |
| 7 | 2160 |
| 8 | 8550 |
| 9 | 31520 |
| 10 | 121716 |
| 11 | 462000 |
| 12 | 1780156 |
| 13 | 6840288 |
| 14 | 26436024 |
| 15 | 102245472 |
| 16 | 396589446 |
| 17 | 1540427328 |
| 18 | 5994280644 |
| 19 | 23356702512 |
| 20 | 91133123796 |
| 21 | 355991626848 |
| 22 | 1392115710024 |
| 23 | 5449199307552 |
| 24 | 21349205067996 |