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 | 4 |
| 2 | 36 |
| 3 | 48 |
| 4 | 1800 |
| 5 | 240 |
| 6 | 35280 |
| 7 | 20160 |
| 8 | 226800 |
| 9 | 50400 |
| 10 | 3659040 |
| 11 | 665280 |
| 12 | 1967565600 |
| 13 | 2242240 |
| 14 | 129729600 |
| 15 | 34594560 |
| 16 | 2677989600 |
| 17 | 66830400 |
| 18 | 1857684628800 |
| 19 | 39109150080 |
| 20 | 3226504881600 |
| 21 | 307286179200 |
| 22 | 2333316585600 |
| 23 | 1285014931200 |
| 24 | 2192556726360000 |
| 25 | 25057791158400 |