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) |
|---|---|
| 3 | 1 |
| 4 | 8 |
| 5 | 59 |
| 6 | 463 |
| 7 | 3978 |
| 8 | 37566 |
| 9 | 388728 |
| 10 | 4385592 |
| 11 | 53653680 |
| 12 | 708126480 |
| 13 | 10034314560 |
| 14 | 152001161280 |
| 15 | 2451821339520 |
| 16 | 41964428419200 |
| 17 | 759698874547200 |
| 18 | 14505012898790400 |
| 19 | 291323663566387200 |
| 20 | 6140173922952652800 |
| 21 | 135515391451776000000 |
| 22 | 3125606951427609600000 |