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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 8 |
| 5 | 32 |
| 6 | 192 |
| 7 | 1152 |
| 8 | 9216 |
| 9 | 82944 |
| 10 | 829440 |
| 11 | 8294400 |
| 12 | 99532800 |
| 13 | 1194393600 |
| 14 | 16721510400 |
| 15 | 250822656000 |
| 16 | 4013162496000 |
| 17 | 64210599936000 |
| 18 | 1155790798848000 |
| 19 | 20804234379264000 |
| 20 | 416084687585280000 |
| 21 | 8737778439290880000 |
| 22 | 192231125664399360000 |