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 | 0 |
| 1 | 4 |
| 2 | 32 |
| 3 | 208 |
| 4 | 1280 |
| 5 | 7744 |
| 6 | 46592 |
| 7 | 279808 |
| 8 | 1679360 |
| 9 | 10077184 |
| 10 | 60465152 |
| 11 | 362795008 |
| 12 | 2176778240 |
| 13 | 13060685824 |
| 14 | 78364147712 |
| 15 | 470184951808 |
| 16 | 2821109841920 |
| 17 | 16926659313664 |
| 18 | 101559956406272 |
| 19 | 609359739486208 |
| 20 | 3656158439014400 |
| 21 | 21936950638280704 |