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) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 16 |
| 4 | 128 |
| 5 | 1152 |
| 6 | 12960 |
| 7 | 269568 |
| 8 | 6635520 |
| 9 | 165888000 |
| 10 | 4561920000 |
| 11 | 209018880000 |
| 12 | 10480803840000 |
| 13 | 513559388160000 |
| 14 | 26454892584960000 |
| 15 | 2106067546275840000 |