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 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 1 |
| 9 | 16 |
| 10 | 272 |
| 11 | 2880 |
| 12 | 32648 |
| 13 | 333696 |
| 14 | 3617545 |
| 15 | 38942336 |
| 16 | 443291226 |
| 17 | 5168682752 |
| 18 | 63523977424 |
| 19 | 807890646528 |
| 20 | 10790865576074 |
| 21 | 149552304296960 |
| 22 | 2168856599259491 |
| 23 | 32631738808727552 |
| 24 | 512002155247238968 |