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 | 0 |
| 2 | 0 |
| 3 | 24 |
| 4 | 1660 |
| 5 | 160524 |
| 6 | 21914632 |
| 7 | 4065598248 |
| 8 | 987830372684 |
| 9 | 304870528356476 |
| 10 | 116578000930637000 |
| 11 | 54116343193686469960 |
| 12 | 29984241542575292762940 |
| 13 | 19548555813018460134901516 |
| 14 | 14815308073366437897483622056 |
| 15 | 12915964646307201385492841052040 |