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 | 6 |
| 3 | 54 |
| 4 | 656 |
| 5 | 10000 |
| 6 | 182952 |
| 7 | 3899224 |
| 8 | 94769152 |
| 9 | 2584929024 |
| 10 | 78145100000 |
| 11 | 2592261435104 |
| 12 | 93586594074624 |
| 13 | 3651967705305088 |
| 14 | 153140949522798720 |
| 15 | 6866498202750000000 |
| 16 | 327772442129447518208 |
| 17 | 16593897777705323921408 |