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 | 11 |
| 2 | 154 |
| 3 | 2618 |
| 4 | 52360 |
| 5 | 1204280 |
| 6 | 31311280 |
| 7 | 908027120 |
| 8 | 29056867840 |
| 9 | 1016990374400 |
| 10 | 38645634227200 |
| 11 | 1584471003315200 |
| 12 | 69716724145868800 |
| 13 | 3276686034855833600 |
| 14 | 163834301742791680000 |
| 15 | 8683217992367959040000 |
| 16 | 486260207572605706240000 |
| 17 | 28689352246783736668160000 |