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 | 1 |
| 3 | 16 |
| 4 | 256 |
| 5 | 4216 |
| 6 | 67456 |
| 7 | 1083136 |
| 8 | 17330176 |
| 9 | 277344816 |
| 10 | 4437547776 |
| 11 | 71001776256 |
| 12 | 1136028420096 |
| 13 | 18176471920896 |
| 14 | 290823550734336 |
| 15 | 4653177071702016 |
| 16 | 74450833163421696 |
| 17 | 1191213334782285596 |
| 18 | 19059413356516569536 |
| 19 | 304950613771087329536 |
| 20 | 4879209820337397272576 |