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) |
|---|---|
| 9 | 1 |
| 10 | 96 |
| 11 | 4256 |
| 12 | 132480 |
| 13 | 3430528 |
| 14 | 80104448 |
| 15 | 1758695424 |
| 16 | 37158281984 |
| 17 | 765948707328 |
| 18 | 15534537453568 |
| 19 | 311681600004096 |
| 20 | 6208696187633664 |
| 21 | 123091007914770432 |
| 22 | 2432892993997766656 |
| 23 | 47996192255918997504 |
| 24 | 945900094339720151040 |
| 25 | 18633845662960307929088 |
| 26 | 367087117998177057243136 |
| 27 | 7234078496745600613089280 |