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 | 12 |
| 2 | 216 |
| 3 | 4320 |
| 4 | 90720 |
| 5 | 1959552 |
| 6 | 43110144 |
| 7 | 960740352 |
| 8 | 21616657920 |
| 9 | 489977579520 |
| 10 | 11171488813056 |
| 11 | 255928652808192 |
| 12 | 5886359014588416 |
| 13 | 135839054182809600 |
| 14 | 3143703825373593600 |
| 15 | 72933928748667371520 |