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 | 4 |
| 4 | 9 |
| 5 | 96 |
| 6 | 190 |
| 7 | 4320 |
| 8 | 11025 |
| 9 | 179200 |
| 10 | 805896 |
| 11 | 36288000 |
| 12 | 63155400 |
| 13 | 5748019200 |
| 14 | 18861448320 |
| 15 | 380872267776 |
| 16 | 4108830350625 |
| 17 | 334764638208000 |
| 18 | 778062273788800 |
| 19 | 115242726703104000 |
| 20 | 310526396168644656 |
| 21 | 15009607805018112000 |
| 22 | 208853182616336294400 |