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 | 8 |
| 2 | 48 |
| 3 | 400 |
| 4 | 2288 |
| 5 | 20112 |
| 6 | 108016 |
| 7 | 1018256 |
| 8 | 5030640 |
| 9 | 51991696 |
| 10 | 229724144 |
| 11 | 2681810832 |
| 12 | 10182741232 |
| 13 | 139998665360 |
| 14 | 430234843632 |
| 15 | 7409690416528 |
| 16 | 16683460826864 |
| 17 | 398259202498704 |
| 18 | 536014603805680 |
| 19 | 21766500736121744 |