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 | 4 |
| 2 | 12 |
| 3 | 120 |
| 4 | 1440 |
| 5 | 24480 |
| 6 | 482400 |
| 7 | 11793600 |
| 8 | 329011200 |
| 9 | 10567065600 |
| 10 | 380131315200 |
| 11 | 15220275840000 |
| 12 | 669519696384000 |
| 13 | 32145251314176000 |
| 14 | 1671451069736448000 |
| 15 | 93606882905023488000 |
| 16 | 5616332944630087680000 |