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) |
|---|---|
| 2 | 1 |
| 3 | 4 |
| 4 | 120 |
| 5 | 3024 |
| 6 | 151200 |
| 7 | 79200 |
| 8 | 1513512000 |
| 9 | 1513512000 |
| 10 | 51459408000 |
| 11 | 74662922880 |
| 12 | 18068427336960 |
| 13 | 133196739984000 |
| 14 | 1215553449093984000 |
| 15 | 173650492727712000 |
| 16 | 3357242859402432000 |
| 17 | 101013513093196704000 |
| 18 | 2043503369875369321920000 |