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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 10 |
| 6 | 0 |
| 7 | 882 |
| 8 | 13312 |
| 9 | 85536 |
| 10 | 561440 |
| 11 | 2276736 |
| 12 | 9471744 |
| 13 | 27991470 |
| 14 | 85725696 |
| 15 | 209107890 |
| 16 | 525062144 |
| 17 | 1116665944 |
| 18 | 2437807104 |
| 19 | 4691672964 |
| 20 | 9234168960 |
| 21 | 16462896030 |
| 22 | 29919532544 |
| 23 | 50215537658 |
| 24 | 85687824384 |
| 25 | 136944081500 |